Qalat, Afghanistan ? Afghan villagers said Thursday that U.S. warplanes had bombed houses, killing several civilians and wounding others, including an infant. U.S. forces suffered their sixth fatality in a week amid rising violence.

Zabul Gov. Ali Khail said U.S.-led coalition forces made “a mistake” during operations against militants in the southern province and that civilians had died. He gave no details.

The U.S. military denied civilians were at the scene of the fighting in Day Chopan district Monday, and the district’s police chief said Taliban insurgents had been hiding in the area. American officials said earlier that 18 suspected Taliban guerrillas and one U.S. service member had been killed in the clash.

Another U.S. service member died Thursday when militants ambushed a group of American military engineers near a road construction project in Paktika province. Another service member was wounded.

The death was the sixth U.S. fatality since Aug. 4, when three U.S. forces were killed in military operations in eastern Afghanistan. One American service member also died Tuesday in a roadside bomb.

The U.S. Defense Department’s Web site says at least 176 American troops have died in and around the country since Operation Enduring Freedom began in late 2001 to topple the Taliban regime. The Web posting was last updated Wednesday.

U.S. forces on Thursday said that a senior Taliban commander was killed in heavy fighting with soldiers from the Afghan army and paratroopers assigned to the U.S. 508th Airborne Infantry Regiment. Qari Amadullah, who commanded as many as 50 fighters, was killed Tuesday near the eastern Afghan city of Wakikwa.

“Killing this individual will significantly disrupt Taliban operations in the region,” said Brig. Gen James G. Champion.

Five other militants were killed and three U.S. troops were wounded.

“The children were crying, and they were very afraid,” said a weeping Sadia Bibi, 50. “These planes killed my relatives. We are poor and innocent people. Why are they killing us?”