Six were killed when their Chinook chopper was shot down and a firefight ensued. It was unclear how the six died. At least 10 U.S. military personnel also were injured.

Another U.S. serviceman died when a helicopter was hit by a rocket-propelled grenade or other launched weapon, but the circumstances also were unclear, the military said. The helicopter managed to fly back to Gardez, capital of the Paktia province in eastern Afghanistan.

In weekend fighting, one U.S. Army soldier and four Afghan fighters died. The soldier was identified Monday as Army Chief Warrant Officer Stanley L. Harriman, 34, of Wade, North Carolina, who was assigned to the 3rd Special Forces Group at Fort Bragg, North Carolina.
Dozens of U.S., coalition and Afghan fighters were wounded in the weekend fighting, but none of the U.S. wounds was life-threatening, authorities said.

Al Qaeda and Taliban forces were under constant bombardment by U.S., allied and Afghan forces for a third straight day in the remote and inhospitable terrain of the Shahi Kot mountains in eastern Afghanistan, U.S. military and Afghan Defense Ministry officials said. B-52s and jet fighters were involved.

*Aircraft have targeted vehicles, mortars, enemy troop locations, caves and anti-aircraft artillery sites,* U.S. Central Command said. *Firefights continue to be intense at times in heavy combat actions. The size of the enemy force is estimated to be several hundred.*

Officials had no estimate of the number of allied forces in the area, where narrow gorges make attack from the ground difficult.

Also Monday, U.S. forces faced small-arms fire in Khost. The troops called in air support, and the small-arms fire ceased, a Central Command spokesman said.

The surge in fighting underscores that the war is by no means over despite reports of diminished activity in recent weeks.

A Central Command spokesman called the joint campaign with Afghan forces the largest offensive in Afghanistan this year. Coalition countries participating in the operation include Australia, Canada, Denmark, France, Germany and Norway.

Over the weekend, U.S. bombers dropped more than 270 precision-guided and gravity bombs, and directed AC-130 gunships at al Qaeda and Taliban forces south of Gardez, said Central Command.

Weather conditions appeared to have aided the coalition's air war this weekend.

*The weather is cold but clear, so there will be no restrictions on aircraft flying in the area, and there is a lot of snow on the ground for the soldiers to slog through,* Central Command's Rear Adm. Craig Quigley said.

The targets include *enemy forces occupying a series of caves complexes* in Paktia province, U.S. Army Maj. A.C. Roper said.

Some AH-64 Apache helicopters were damaged by enemy fire, Central Command added.

The United States has maintained a base in Gardez for two months, recruiting and training Afghan fighters, sources said.

U.S. military officials said Saturday that a thermobaric bomb was dropped on a cave in the region, but they would not identify the target.

Thermobaric warheads are designed to destroy targets hidden in caves, with *fuel-rich* warheads that can fill tunnels with fireballs.

The operation began Friday night with U.S. B-52 airstrikes at Shahi Kot aimed at al Qaeda and Taliban holdouts, Afghan and U.S. officials said.

Officials said the bombing was followed early Saturday by 500 to 600 Afghan soldiers on the ground and U.S. troops from the 101st Airborne Division, based at the Kandahar International Airport in southern Afghanistan.

Fighting Sunday morning also was reported in Lowgar, about 50 miles south of the capital, Kabul. The Afghanistan Intelligence Ministry said about 500 al Qaeda and Taliban forces were beaten back by forces loyal to the interim administration, supported by U.S. airstrikes.

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