U.S. Takes Over Deadly Afghan District from U.K.

Britain's military handed the U.S. responsibility Monday for a dangerous district in southern Afghanistan that has been the scene of some of the bloodiest fighting by British troops.

NATO said the 40 Commando Royal Marines were being reassigned throughout central Helmand province, which remains a volatile battleground even though tens of thousands of foreign and Afghan troops moved into the area in February.

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British troops arrived in Helmand's Sangin district in 2006 and have partnered with Afghan national security forces to provide security to allow governance and economic development to take root. Since the conflict began in 2001, Britain has lost 337 troops in Afghanistan, including more than 100 in Sangin.

"British forces have served in Sangin over the last four years and should be very proud of the achievements they have made in one of the most challenging areas of Afghanistan," British defense secretary Liam Fox said.

Under the new NATO deployment plan, which was announced in July, the U.S. will operate mainly in the north and south of Helmand, with British, Danish and Estonian troops working in the heavily populated central areas.

Lt. Gen. David Rodriguez, the No. 2 American general in Afghanistan and the operational chief for the allied forces, said in July the British move was part of his effort to consolidate and better organize forces in Helmand.

Rodriguez rejected the notion the U.S. was bailing out British forces, noting Britain has taken high losses in Sangin.

The U.S. military has focused much of its attention on pushing the Taliban out of Kandahar and Helmand provinces in the south, but as CBS News Anchor Katie Couric reported, some of the toughest battles are being fought in Kunar province, in the northeast.

The region's mountains and proximity to Pakistan make it a haven for insurgents.

CBS News partner GlobalPost recently published dramatic footage of American soldiers being ambushed in Kunar.

Watch the Entire Video at GlobalPost

On Sunday, a joint Afghan and coalition force detained several suspected Taliban insurgents and seized 45 pounds of opium in neighboring Nahri Sarraj district of Helmand, the coalition said. The joint force was tracking a Taliban bomb-maker who specialized in building detonators for improvised explosive devices.