A mammoth B-52 bomber was called into combat for the first time in five months Sunday to protect U.S. special forces battling armed Afghans outside an American base. No U.S. soldiers were injured during the shootout in western Afghanistan, but at least 11 Afghans were killed in factional fighting, U.S. and local officials said. The battle began when a group of U.S. special forces patrolling outside Shindand air base stopped a group of armed Afghans on the roadside, U.S. military spokesman Col. Roger King said.

When the patrol stopped, the Afghans opened fire, King said.

The Americans returned fire, then called for air support while making their escape, King said. The B-52 bomber dropped seven 2,000-pound laser-guided bombs.

The last time U.S. forces reported using a B-52 in combat in Afghanistan was a July 1 attack in central Uruzgan province, when Afghan authorities say 48 civilians were killed and 117 were injured.

In that attack, a B-52 struck suspected al-Qaida and Taliban cave and bunker complexes, while an AC-130 gunship strafed several villages. U.S. officials said they believed the villages were legitimate targets.

Sunday's incident occurred as forces loyal to Ammanullah Khan, an ethnic Pashtun commander, and rival Ismail Khan clashed in the region. The fighting has forced thousands of residents to flee from at least 500 homes near the front line.

Ammanullah Khan accused his longtime adversary's ethnic Tajik forces of ordering a massive attack Saturday night - using tanks, artillery and rocket launchers - on his positions in Zer-e-Koh district, about 15 miles south of Shindand.

Ammanullah Khan said the fighting continued Sunday as his forces tried to repel Ismail Khan's forces. Late Sunday, Ismail Khan's fighters fired down on Zer-e-Koh with truck-mounted multiple rocket launchers positioned in nearby mountains, he said.

Ammanullah Khan said American planes dropped at least six bombs near front line positions at Zer-e-Koh - not Shindand.

"Bombs exploded on Ismail Khan's side and others exploded on our side. We think the Americans were dropping bombs to end the fighting," Ammanullah Khan said, adding that he had no contact with U.S. special forces and had not seen any in the area.

King said the bombing had nothing to do with the factional fighting and U.S. forces "never get involved" in disputes between rival warlords.

Ammanullah Khan said 11 of his fighters were killed and seven others were wounded. Neither side made any territorial advances, he said.

Neither Ismail Khan nor his deputies were available for comment.

Ammanullah Khan said he had called Kabul to inform President Hamid Karzai's government about the fighting and to request that the central government intervene and disarm both sides.

However, Karzai has little authority outside Kabul. The rest of the country is in the hands of regional warlords with private armies at their disposal.

Ismail Khan, a former governor, regained control of Herat after U.S.-led forces ousted the hardline Taliban regime last year.

But local Pashtuns complain that his forces have looted the area and oppressed them.

Also Sunday, unidentified attackers fired four rockets at an American-controlled airport in the eastern city of Khost, King and a local government official said.

A vehicle parked near the airport's gate exploded soon after the attack, with shrapnel slightly injuring one U.S. soldier in the arm, King said. The rockets were believed to have been fired from the vehicle and the attackers fled before U.S. troops arrived, he said.

U.S. forces based in eastern Afghanistan are hunting al-Qaida and Taliban fugitives near the Pakistan border. Unknown attackers sometimes fire rockets and other weapons at the troops or their bases, but they rarely hit their target.

On Wednesday, gunmen ambushed a U.S. special forces convoy near the eastern town of Gardez, wounding one American soldier in the leg. Meanwhile, Afghan security forces arrested eight Afghans in Chapar Har village in eastern Nangarhar province, state radio said.

Provincial commander Hazrat Ali said the eight men were al-Qaida members linked to recent rocket attacks in the area.

In Kabul, police seized six tiny bombs in the northwestern Taimani neighborhood, Interior Ministry spokesman Alishah Paktiawal said. The bombs were not rigged to detonate.

And in the southern city of Kandahar, police fought a brief gunbattle with militiamen loyal to Gov. Gul Agha Sherzai after one side seized three vehicles and tried to disarm some men from the other side, police official Shoiab Khan said. Three people were killed before tribal elders intervened to end the clash.

PHOTO CAPTION

Members of the Coalition Joint Task Force carry their firearms with them as they watch a Romanian concert Sunday, Dec. 1, 2002 at Bagram Air Base in Afghanistan. (AP Photo/Pat Roque)