KABUL (Reuters) - Twelve people were killed on Friday in the bloodiest day yet in protests that have raged across Afghanistan over the desecration of copies of the Muslim holy book at a NATO military base with riot police and soldiers on high alert braced for more violence. 
 
 The burning of the Korans at the Bagram compound earlier this week has deepened public mistrust of NATO forces struggling to stabilize Afghanistan before foreign combat troops withdraw in 2014. 
 
 Hundreds of Afghans marched toward the palace of Afghan President Hamid Karzai in Kabul, while on the other side of the capital protesters hoisted the white flag of the Taliban. 
 
 Chanting "Death to America!" and "Long live Islam!," protesters also threw rocks at police in Kabul, while Afghan army helicopters circled above. 
 
 Friday is a holy day and the official weekly holiday in Afghanistan and mosques in the capital drew large crowds, with police in pick-up trucks posted on nearby streets. 
 
 Armed protesters took refuge in shops in the eastern part of the city, where they killed one demonstrator, said police at the scene. In another Kabul rally, police said they were unsure who fired the shots that killed a second protester. 
 
 Seven more protesters were killed in the western province of Herat, two more in eastern Khost province and one in the relatively peaceful northern Baghlan province, health and local officials said. In Herat, around 500 men charged at the U.S. consulate. 
 
 U.S. President Barack Obama had sent a letter to Karzai apologizing for the unintentional burning of the Korans at NATO's main Bagram air base, north of Kabul, after Afghan laborers found charred copies while collecting rubbish. 
 
 Muslims consider the Koran to be the literal word of God and treat each copy with deep reverence. Desecration is considered one of the worst forms of blasphemy. 
 
 Afghanistan wants NATO to put those responsible on public trial. 
 
 In neighboring U.S. ally Pakistan, about 400 members of a hardline Islamist group staged protests. "If you burn the Koran, we will burn you," they shouted. 
 
 To Afghanistan's west, Iranian cleric Ahmad Khatami said the U.S. had purposely burned the Korans. "These apologies are fake. The world should know that America is against Islam," he said in a speech broadcast live on state radio. 
 
 "It (the Koran burning) was not a mistake. It was an intentional move, done on purpose." 
 
 Most Westerners have been confined to their heavily fortified compounds, including at the sprawling U.S. embassy complex and other diplomatic missions, as protests that have killed a total of 23 people, including two U.S. soldiers, rolled into their fourth day. The embassy, in a message on the microblogging site Twitter, urged U.S. citizens to "please be safe out there" and expanded movement restrictions to relatively peaceful northern provinces, where large demonstrations also occurred Thursday, including the attempted storming of a Norwegian military base. 
 
 The Taliban urged Afghan security forces Thursday to "turn their guns on the foreign infidel invaders" and repeatedly urged Afghans to kill, beat and capture NATO soldiers. 
 
 Germany, which has the third-largest foreign presence in the NATO-led war, pulled out several weeks early of a small base in the northern Takhar province Friday over security concerns, a defense ministry spokesman said. 
 
 (Additional reporting by Amira Mitri in TEHRAN, Imtiaz Shah in KARACHI, Sabine Siebold in BERLIN, Writing by Amie Ferris-Rotman; Editing by Michael Georgy and Ed Lane) ||||| It was unclear on Friday night whether, after four days of protests, the violence that has rolled through the country was finally spent, or if the Koran burning had uncorked an inexhaustible well of fury over the continuing presence of Western troops after 10 years of war. In some measure, the angry demonstrations were to be expected in a religious country fed up with foreigners, but the tension this week seems more pervasive and irresolvable than in the past. 
 
 “The violence is almost within the normal realm of things that you would see after this kind of incident,” said Martine Van Bijlert, a co-director of the Afghanistan Analysts Network, a policy and research institute in Kabul. “The big question is, how long does it go on? You have to watch who jumps on the bandwagon. It is very intense, and there’s the feeling that all areas need to have had their own demonstration if they haven’t had one yet.” 
 
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 The worst violence Friday was in Herat Province, in the West on the Iranian border, where seven people were killed. Protesters there were armed and some appeared to be agents provocateurs, government officials said. 
 
 “People were on their way home after the prayer when a number of opposition and agitator people, misusing the pure emotions of the people, urged them to go toward the United States Consulate in the city,” said Mohyaddin Noori, the spokesman for Herat’s provincial governor. “On the way to the consulate, some of these riotous people who were armed opened fire and were throwing rocks.” 
 
 One of the vehicles hit by gunfire was a police truck full of ammunition, which exploded, sending bullets in all directions and wounding 65 people, he said. 
 
 Several Heratis suggested that Iranian agents were at work behind the scenes. Some noted that Radio Mashad, an Iranian station, had urged action against Western interests in Afghanistan, taking advantage of a moment when people’s emotions were running high, said Mohammed Rafiq Shaheer, a professor of political science at Herat University. He noted that protesters appeared to have been directed to march towards the American Consulate by mullahs in several areas of the city. 
 
 He said that he blamed Pakistani and Iranian intelligence. Both agencies, he said, “have invested a lot in this country and they have people loyal to them, and this is a perfect time for the intelligence apparatus of the neighboring countries to ignite people’s fiery emotions which would lead them to violence.” 
 
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 Two protesters died in Khost Province, near the Pakistan border, and one in Baghlan Province. 
 
 In Kabul, despite larger numbers of protesters on the streets, only a handful were injured. 
 
 Interior Minister Bismullah Khan adopted a nuanced strategy that encouraged the protesters to express themselves peacefully, but also put in place a phalanx of police units to keep the most menacing from making their way to the center of the city. 
 
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 Riot police officers backed up by heavily armed special units in some 40 police trucks faced down an estimated 4,000 men wielding rocks and sticks after Friday Prayer. At one point as the two groups neared each other, protesters threw rocks and shouted, but the police did not fire and eventually moved the protesters back. 
 
 A few of the protesters were waving the Taliban’s white flag, some wore head wrappings bearing the jihad slogan “I sacrifice myself,” and protesters throughout the city shouted “Death to America.” 
 
 The police also broke up another crowd of about 1,000 in central Kabul, first by driving trucks into the crowd to disperse it and then by chasing the protesters on foot and hitting them with rubber batons. 
 
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 Some officers said they did the job despite sympathizing with the protesters. 
 
 “We try to stop the demonstrators from violence and looting,” said a Kabul police officer, Azizullah, 40, who uses only one name. “That is our job, but If I were an ordinary person, not a policeman, I would have joined the demonstrations.” 
 
 NATO said it was still investigating what led to the decision to burn Korans and other religious texts. Early reports said that the books had inflammatory messages written in them from detained Taliban suspects. Most of the Korans that were rescued from the flames are still at Bagram Air Base in a locked container. They are viewed as evidence, a NATO spokesman said. A few of the Korans were taken out of the base by Afghan employees. 
 
 The absence of lethal violence in Kabul belies a deep frustration that appeared in interviews with police officers and protesters alike, a sense that justice has not yet been done and a suspicion that the United States, while apologizing, will not hold anyone to account. 
 
 “Just by saying ‘I am sorry,’ nothing can be solved,” said Wali Mohammed, one of the protesters. “We want an open trial for those infidels who have burned our Holy Koran.” 
 
 Mohammed Anwar, an off-duty police officer, had joined the protesters on Friday and seemed barely able to contain his fury. “I will take revenge from the infidels for what they did to our Holy Koran, and I will kill them whenever I get the chance,” he said as he walked with crowd of protesters wielding rocks and sticks. “I don’t care about the job I have.” ||||| Germany says it has withdrawn troops from an outpost in northern Afghanistan amid protests over the burning of Qurans at a U.S. base. 
 
 Defense Ministry spokesman Stefan Paris said the German military, which handed over security responsibility for the Taloqan area to Afghan authorities on Feb. 15, had originally planned to shut down its base there altogether in late March. 
 
 But, he said Friday, the regional commander decided in view of demonstrations in Taloqan and elsewhere in the north _ which led to injuries but no deaths _ that the 50 remaining German soldiers should pull back to a larger base in Kunduz immediately. 
 
 Paris says the soldiers already have made the roughly 43-mile (70-kilometer) transfer to Kunduz and have taken most material from the Taloqan outpost with them. 
 
 Germany has nearly 4,800 troops in northern Afghanistan.
– Protesters are rallying once again to decry the burning of Korans at Bagram, with more shouts of "death to America"—and deaths—throughout the country. The New York Times reports that gunfire was audible as demonstrators assembled at a Kabul mosque following Friday prayers. Another 4,000 people carrying sticks and rocks moved toward the center of the city; some waved Taliban flags and had a jihadist slogan written on their clothes: "I sacrifice myself." Demonstrations occurred in at least six more provinces throughout Afghanistan, and Reuters reports that nine more were killed today: seven in the western province of Herat, and two in Khost in the east. Meanwhile, Germany says it has withdrawn troops from an outpost in northern Afghanistan amid the protests. The German military had planned to shutter its base in the Taloqan area in late March, but the 50 remaining soldiers have been transferred out of the base in light of the demonstrations, reports the AP. And at home, Obama is facing GOP criticism for his apology.