A military spokesman for the US-led International Security Assistance Force said the US troops responded to the attacks near the city of Asadabad and sent a B-52 bomber and two fighter jets scrambling in the air to pound a suspected rebel position.

“A B-52 responded first, then two AV-8 Harriers. The B-52 dropped a joint direct attack munitions bomb and the Harriers dropped one 1,000-pound laser-guided bomb on enemy fighters observed at the suspected location,” the spokesman Colonel Rodney Davis said.

He further said the US-led troops were assessing the scene of the battle to determine whether any of the Afghan fighters had been killed by the bombing raids.

Davis said a group of Afghan fighters had been spotted “on the ground, in the open,” but it was not clear how large the group was.

'The B-52 dropped a joint direct attack munitions bomb and the Harriers dropped one 1,000-pound laser-guided bomb on enemy fighters'

--US military spokesman

Meanwhile, a rocket was fired at another US base at Ghecko to the northwest of Kandahar.

The rocket landed harmlessly and no casualties were reported.

The latest attacks came as US Central Command chief General, John Abizaid was on a visit to Afghanistan.

General Abizaid landed at the Bagram air base to the north of Kabul on Wednesday. He is scheduled to meet Afghanistan’s interim leader Hamid Karzai on Thursday.

Despite having toppled the Taliban in December 2001, US-led forces in Afghanistan have come under increasing attacks in recent months.

About 11,5000 troops, the majority of them Americans, are scouring Afghanistan’s countryside for Taliban forces and their allies.