Eight police officers were hurt and 18 protesters arrested in Seattle on Wednesday when a May Day rally that began peacefully turned violent after dark, with crowds hurling rocks and bottles at police who responded with pepper spray grenades. Protesters threw rocks, bottles and chunks of asphalt at officers, officials said, smashing store and car windows, overturning trash cans and lining up newspaper display racks to block streets. Police in riot gear, some riding in armored SWAT vehicles, responded by repeatedly firing 'blast ball' grenades, which emit smoke tinged with pepper spray. 'We're a bigger, better city than this,' Mayor Mike McGinn said at a news conference. 'I'm disappointed that this is the picture the world sees of us.' Scroll down for video . Tension: A protester walks away after placing a smoke device on the ground in front of police officers during a May Day march that began as an anti-capitalism protest and turned into demonstrators clashing with police . Violent: Eight police officers were hurt and 18 protesters arrested in Seattle on Wednesday when a May Day rally that began peacefully turned violent after dark . Reaction: Police in riot gear, some riding in armored SWAT vehicles, responded by repeatedly firing "blast ball" grenades, which emit smoke tinged with pepper spray . 'We're a bigger, better city than this,' Mayor Mike McGinn said at a news conference. 'I'm disappointed that this is the picture the world sees of us' Tension: A man who was pepper sprayed is attended to using milk and right protestors react as a police flash-bang grenade goes off . Authorities: A protester who was arrested lies on the ground next to police batons during the May Day demonstration . Stand off: Several dozen protesters, many using bandanas to cover their faces, began clashing with police in downtown Seattle hours after a peaceful immigrant-rights march ended . Damage: A woman points out a broken window to a Seattle Police officer along the route of a May Day march . Most of the 150-200 protesters who had . stayed on the street after darkness fell for a 'non-permitted' protest . had dispersed by midnight. 'We did not start to take action until . that group itself started to act violently towards the officers and the . community at large,' Assistant Police Chief Paul McDonagh said. Several dozen protesters, many using . bandanas to cover their faces, began clashing with police in downtown . Seattle hours after a peaceful immigrant-rights march ended. Protesters . threw rocks and bottles at police officers and news crews. As they . moved through downtown Seattle to another neighborhood, they flung . construction street barriers, trash cans and newspaper bins on the . streets in an attempt to stop police officers. One protester was seen using a skateboard to smash windows at a Walgreens drug store in the city's Capitol Hill neighborhood, and others overturned trash cans and lined up newspaper display racks to block police. Windows of businesses were broken and vehicles with people in them were banged around. Police used their bikes to shield businesses and eventually began to use pepper spray and 'flash bang' grenades - releasing a flash of light, smoke and a loud noise - to disperse the crowd. But that pushed the group to another nearby neighborhood, and they left a wake of overturned trash cans and debris on the street. Anger: Protesters threw rocks and bottles at police officers and news crews. As they moved through downtown Seattle to another neighborhood, they smashed shop windows . Injured: Seattle police said in a tweet that one officer was injured by a thrown object. His condition was not immediately clear . Burning: A demonstrator has milk put in his eyes to help stop the stinging of pepper spray . Officers in riot gear, some riding in armored SWAT vehicles, repeatedly fired the grenades and tried to disperse the crowd. Seattle police department said that one officer was injured after being hit by an object. Initially, the protesters concentrated on a business sector of downtown Seattle. This is the second year in a row violence has broken out during May Day in Seattle. Last year, anarchists broke windows of store fronts, including Niketown, and vehicles and used smoke bombs. Protesters also targeted a federal building, breaking windows and doors. The violence broke out as darkness fell in Seattle following a day of May Day rallies in cities across the U.S. West that were planned by a coalition of organized labor activists, students, civil rights advocates and members of the clergy to call for an overhaul of immigration laws. Arrest: A protester who was arrested during a May Day march. Officers in riot gear, some riding in armored SWAT vehicles, repeatedly fired the grenades and tried to disperse the crowd . Outbreak: The violence broke out as darkness fell in Seattle following a day of May Day rallies in cities across the U.S. West that were planned by a coalition of organized labor activists, students, civil rights advocates and members of the clergy to call for an overhaul of immigration laws . Preparation: Riot police prepare to confront demonstrators in Capitol Hill as the days gives way to night . Lit up:Protesters react as a firework is set off during May Day protests in downtown Seattle . Protesters and media run from a police munition during a May Day protest in Seattle Wednesday May 1, 2013. Police used flash bangs and pepper spray against some protesters pelting them with objects late on Wednesday . Demonstrators back away from a "flash bang" object used by police during a May Day protest in Seattle Wednesday, May 1, 2013 . Seattle Police officers try to clear an intersection of protesters during a May Day march that began as an anti-capitalism protest and turned into demonstrators clashing with police . A Seattle Police officer sprays pepper spray on protesters during a May Day march . Olivia One Feather of Covington . joined the crowd Wednesday night because she wanted to see how police . handled the protest. She said she wasn't impressed, adding that she was . pepper sprayed in the face while trying to video record officers. 'They don't have any manners. They don't say please or give you time to get out of the way,' she said. Of . the protesters, she added, 'They're doing what we need to do to stand . up to ourselves. These are our streets and we have the right to take . them.' Many of the . protesters are self-described anarchists. A local anarchist website said . protesters would attempt to disrupt the day. The violence marred a May Day that immigrant-rights activists hoped would put a focus back on immigration reform. Thousands . of people marched about 2 1/2 miles from the Central District toward . Seattle's downtown Jackson Federal Building after a May Day rally . supporting immigrant rights and labor. Many . carried signs, with messages such as 'We are America,' and 'There are . no illegal humans.' One sign suggested forgetting about marijuana and . instead asking the United States to 'Legalize my mom,' a reference to . Washington's recent legalization of marijuana. Other . demonstrations and rallies in Olympia, Mount Vernon, Spokane, . Vancouver, Walla Walla, Wenatchee and Yakima went along peacefully. In . Los Angeles, thousands of protesters marched through downtown Los . Angeles waving American flags and carrying signs with the slogan, 'Stop . deportations.' The . demonstrators chanted in Spanish, 'Obama! Escucha! Estamos en la lucha!' ('Obama! Listen! We are in the fight!'), as they marched under sunny . skies down one of downtown's main thoroughfares. Police officers arrest a man on a sidewalk during a May Day protest in New York. People around the world mark the first of May to call for worker's rights and support the labor movement . A police officer tries to arrest a man wearing a mask during a May Day protest in New York, New York, USA . Police officers work to restrain a protester during May Day rallies in New York, Wednesday, May 1, 2013 . Police officers arrest people affiliated with the Occupy Wall Street protest in New York May 1, 2013 . Activists in New York City are protesting working conditions, immigration reform and other issues . A Seattle Police officer swings his baton at protesters as they move away . The march spanned across more than two large city blocks, and one police officer told Reuters that unofficial estimates put the size of the crowd at roughly 3,500 people. No arrests were reported. In Arizona, where a state crackdown against illegal immigration was signed into law three years ago, several hundred people joined a late-afternoon rally outside the state Capitol in Phoenix, ahead of a march through downtown. The protests come about two weeks after a bipartisan group of U.S. senators introduced an 844-page bill, backed by President Barack Obama, that would rewrite many of America's immigration laws. A centerpiece of the measure would create a path to legal status and ultimately citizenship for many of the 11 million undocumented immigrants in the United States. It also aims to secure the U.S. border with Mexico against illegal entry and to make it easier for industry, particularly high-tech businesses and agriculture, to hire workers from abroad when needed. The demonstrators chanted in Spanish, "Obama! Escucha! Estamos en la lucha!" ("Obama! Listen! We are in the fight!"), as they marched under sunny skies down one of downtown's main thoroughfares . Marchers walk along during a rally in downtown Los Angeles. In celebration of May Day thousands have gathered for an immigration reform rally in downtown . Saul Linares participates in an immigration reform May Day rally in Union Square in New York, Wednesday, May 1 .
Police used 'flash bangs' and pepper spray .
against some protesters who pelted them with rocks and bottles late .
Wednesday, as violence erupted during May Day in Seattle .
In Los Angeles, thousands of protesters marched .
through downtown Los Angeles waving American flags and carrying signs .
with the slogan,  'Stop deportations.'
Arrests in New York as May Day protests witnessed pockets of violence .
Eight police officers were hurt and 18 protesters arrested in Seattle on Wednesday when a May Day rally that began peacefully turned violent after dark, with crowds hurling rocks and bottles at police who responded with pepper spray grenades. Protesters threw rocks, bottles and chunks of asphalt at officers, officials said, smashing store and car windows, overturning trash cans and lining up newspaper display racks to block streets. Police in riot gear, some riding in armored SWAT vehicles, responded by repeatedly firing 'blast ball' grenades, which emit smoke tinged with pepper spray. 'We're a bigger, better city than this,' Mayor Mike McGinn said at a news conference. 'I'm disappointed that this is the picture the world sees of us.' Scroll down for video . Tension: A protester walks away after placing a smoke device on the ground in front of police officers during a May Day march that began as an anti-capitalism protest and turned into demonstrators clashing with police . Violent: Eight police officers were hurt and 18 protesters arrested in Seattle on Wednesday when a May Day rally that began peacefully turned violent after dark . Reaction: Police in riot gear, some riding in armored SWAT vehicles, responded by repeatedly firing "blast ball" grenades, which emit smoke tinged with pepper spray . 'We're a bigger, better city than this,' Mayor Mike McGinn said at a news conference. 'I'm disappointed that this is the picture the world sees of us' Tension: A man who was pepper sprayed is attended to using milk and right protestors react as a police flash-bang grenade goes off . Authorities: A protester who was arrested lies on the ground next to police batons during the May Day demonstration . Stand off: Several dozen protesters, many using bandanas to cover their faces, began clashing with police in downtown Seattle hours after a peaceful immigrant-rights march ended . Damage: A woman points out a broken window to a Seattle Police officer along the route of a May Day march . Most of the 150-200 protesters who had . stayed on the street after darkness fell for a 'non-permitted' protest . had dispersed by midnight. 'We did not start to take action until . that group itself started to act violently towards the officers and the . community at large,' Assistant Police Chief Paul McDonagh said. Several dozen protesters, many using . bandanas to cover their faces, began clashing with police in downtown . Seattle hours after a peaceful immigrant-rights march ended. Protesters . threw rocks and bottles at police officers and news crews. As they . moved through downtown Seattle to another neighborhood, they flung . construction street barriers, trash cans and newspaper bins on the . streets in an attempt to stop police officers. One protester was seen using a skateboard to smash windows at a Walgreens drug store in the city's Capitol Hill neighborhood, and others overturned trash cans and lined up newspaper display racks to block police. Windows of businesses were broken and vehicles with people in them were banged around. Police used their bikes to shield businesses and eventually began to use pepper spray and 'flash bang' grenades - releasing a flash of light, smoke and a loud noise - to disperse the crowd. But that pushed the group to another nearby neighborhood, and they left a wake of overturned trash cans and debris on the street. Anger: Protesters threw rocks and bottles at police officers and news crews. As they moved through downtown Seattle to another neighborhood, they smashed shop windows . Injured: Seattle police said in a tweet that one officer was injured by a thrown object. His condition was not immediately clear . Burning: A demonstrator has milk put in his eyes to help stop the stinging of pepper spray . Officers in riot gear, some riding in armored SWAT vehicles, repeatedly fired the grenades and tried to disperse the crowd. Seattle police department said that one officer was injured after being hit by an object. Initially, the protesters concentrated on a business sector of downtown Seattle. This is the second year in a row violence has broken out during May Day in Seattle. Last year, anarchists broke windows of store fronts, including Niketown, and vehicles and used smoke bombs. Protesters also targeted a federal building, breaking windows and doors. The violence broke out as darkness fell in Seattle following a day of May Day rallies in cities across the U.S. West that were planned by a coalition of organized labor activists, students, civil rights advocates and members of the clergy to call for an overhaul of immigration laws. Arrest: A protester who was arrested during a May Day march. Officers in riot gear, some riding in armored SWAT vehicles, repeatedly fired the grenades and tried to disperse the crowd . Outbreak: The violence broke out as darkness fell in Seattle following a day of May Day rallies in cities across the U.S. West that were planned by a coalition of organized labor activists, students, civil rights advocates and members of the clergy to call for an overhaul of immigration laws . Preparation: Riot police prepare to confront demonstrators in Capitol Hill as the days gives way to night . Lit up:Protesters react as a firework is set off during May Day protests in downtown Seattle . Protesters and media run from a police munition during a May Day protest in Seattle Wednesday May 1, 2013. Police used flash bangs and pepper spray against some protesters pelting them with objects late on Wednesday . Demonstrators back away from a "flash bang" object used by police during a May Day protest in Seattle Wednesday, May 1, 2013 . Seattle Police officers try to clear an intersection of protesters during a May Day march that began as an anti-capitalism protest and turned into demonstrators clashing with police . A Seattle Police officer sprays pepper spray on protesters during a May Day march . Olivia One Feather of Covington . joined the crowd Wednesday night because she wanted to see how police . handled the protest. She said she wasn't impressed, adding that she was . pepper sprayed in the face while trying to video record officers. 'They don't have any manners. They don't say please or give you time to get out of the way,' she said. Of . the protesters, she added, 'They're doing what we need to do to stand . up to ourselves. These are our streets and we have the right to take . them.' Many of the . protesters are self-described anarchists. A local anarchist website said . protesters would attempt to disrupt the day. The violence marred a May Day that immigrant-rights activists hoped would put a focus back on immigration reform. Thousands . of people marched about 2 1/2 miles from the Central District toward . Seattle's downtown Jackson Federal Building after a May Day rally . supporting immigrant rights and labor. Many . carried signs, with messages such as 'We are America,' and 'There are . no illegal humans.' One sign suggested forgetting about marijuana and . instead asking the United States to 'Legalize my mom,' a reference to . Washington's recent legalization of marijuana. Other . demonstrations and rallies in Olympia, Mount Vernon, Spokane, . Vancouver, Walla Walla, Wenatchee and Yakima went along peacefully. In . Los Angeles, thousands of protesters marched through downtown Los . Angeles waving American flags and carrying signs with the slogan, 'Stop . deportations.' The . demonstrators chanted in Spanish, 'Obama! Escucha! Estamos en la lucha!' ('Obama! Listen! We are in the fight!'), as they marched under sunny . skies down one of downtown's main thoroughfares. Police officers arrest a man on a sidewalk during a May Day protest in New York. People around the world mark the first of May to call for worker's rights and support the labor movement . A police officer tries to arrest a man wearing a mask during a May Day protest in New York, New York, USA . Police officers work to restrain a protester during May Day rallies in New York, Wednesday, May 1, 2013 . Police officers arrest people affiliated with the Occupy Wall Street protest in New York May 1, 2013 . Activists in New York City are protesting working conditions, immigration reform and other issues . A Seattle Police officer swings his baton at protesters as they move away . The march spanned across more than two large city blocks, and one police officer told Reuters that unofficial estimates put the size of the crowd at roughly 3,500 people. No arrests were reported. In Arizona, where a state crackdown against illegal immigration was signed into law three years ago, several hundred people joined a late-afternoon rally outside the state Capitol in Phoenix, ahead of a march through downtown. The protests come about two weeks after a bipartisan group of U.S. senators introduced an 844-page bill, backed by President Barack Obama, that would rewrite many of America's immigration laws. A centerpiece of the measure would create a path to legal status and ultimately citizenship for many of the 11 million undocumented immigrants in the United States. It also aims to secure the U.S. border with Mexico against illegal entry and to make it easier for industry, particularly high-tech businesses and agriculture, to hire workers from abroad when needed. The demonstrators chanted in Spanish, "Obama! Escucha! Estamos en la lucha!" ("Obama! Listen! We are in the fight!"), as they marched under sunny skies down one of downtown's main thoroughfares . Marchers walk along during a rally in downtown Los Angeles. In celebration of May Day thousands have gathered for an immigration reform rally in downtown . Saul Linares participates in an immigration reform May Day rally in Union Square in New York, Wednesday, May 1 .
row violence has broken out during May Day in in Seattle Wednesday May 1, 2013. Police used flash bangs and pepper spray against some along peacefully. In . Los Angeles, thousands of protesters marched through downtown Los . Angeles waving American flags and carrying signs with the slogan, 'Stop . deportations.' The . New York, Wednesday, May 1, 2013 . Police