districts in central Helmand , and stretch to Rig district in the south , Pelletier said . Marines and Afghan forces have taken over the key town of Khan Neshin , the capital of Rig district , which had been under Taliban control , the Marine source said . The goal is to protect residents from the threat of Taliban and other insurgent intimidation and violence , Pelletier said . `` Our focus is now and will remain the Afghan people . We have worked closely with local Helmand government officials and many tribal and local leaders in the detailed planning of this major offensive , '' said Brig. Gen. Larry Nicholson , commander of Task Force Leatherneck . Once security is established , civil affairs personnel and other nongovernmental groups and agencies can come in and establish programs . However , Taliban control of the countryside is so extensive in provinces such as Helmand and Kandahar to the east that security forces face a tough job , according to a report this week in The New York Times . The government has no involvement in five of Helmand 's 13 districts , the report said . In the fighting
KABUL , Afghanistan -LRB- CNN -RRB- -- U.S. Marines on Friday kept up a major push against entrenched militants in southern Afghanistan in an attempt to rout the Taliban from their stronghold in Helmand province , Marine Capt. William Pelletier said . A U.S. Marine patrols Garmser district in Afghanistan 's Helmand province on Friday . A Marine source described Thursday evening 's fighting in the Helmand River Valley as `` our most significant encounter . '' Sporadic fighting that began earlier Thursday stretched over several hours in the southeastern sector of Garmser district , said Pelletier , spokesman for the Marine Expeditionary Brigade-Afghanistan . Helmand province , a poppy-growing region , is the focus of the U.S.-led Operation Khanjar . Afghanistan supplies 90 percent of the world 's opium , which is used in the production of heroin . The forces are attempting to gain and hold ground in the perilous region ahead of Afghan national elections in August . Almost 4,000 Marines and sailors from the expeditionary brigade , along with more than 600 Afghan national security forces , are operating in key population centers along the valley , Pelletier said . Their targets are Garmser and Nawa