Updated

American troops backed by air support killed three people in overnight raids on suspected militants in southeastern Afghanistan (search), the military said Friday, and U.S. forces were reported by Afghan officials to have killed three Taliban (search) commanders elsewhere.

Separately, two police officers were shot dead after escorting U.N. staff in the west, part of a wave of violence threatening plans for landmark September elections.

The U.S. military said that three suspected militants were killed and 23 people detained after four U.S. soldiers were shot and wounded during raids Thursday against militia forces in Tani district, part of the volatile Khost province, 150 miles south of the capital, Kabul.

The injured soldiers were taken to the main U.S. base at Bagram (search), north of Kabul. Their wounds were not life-threatening, military spokeswoman Master Sgt. Cindy Beam said.

Beam said that "precision air support was used and all rounds were on target."

But residents and Afghan officials gave a different account, saying a U.S. patrol was driving through Tani when a resident on edge because of a local feud fired on the vehicles in darkness, fearing they were part of a plot against him.

"He didn't know they were Americans," said Mirza Jan Nimgaray, mayor of Bak, another district of Khost. "The Americans fired back, called in the plane and it destroyed his house completely."

Footage shot by Associated Press Television News showed the corpses of two young men wrapped in bloodied sheets inside a mud-walled compound. The main gate was riddled by bullets, and there were holes in the walls of the house.

A villager, who didn't give his name, told APTN the two dead men were nephews of Mir Sayed, the man who opened fire on the Americans. The wife of a laborer on Sayed's farm was also killed, he said.

Further south, Khalid Pashtun, spokesman for the provincial government in Kandahar, said that U.S. forces killed three Taliban commanders and arrested five more members of the hardline militia, which was ousted at the end of 2001 for harboring Usama bin Laden (search).

Pashtun said the biggest catch in Tuesday's operation was Mullah Shahzada (search), the Taliban's provincial commander, who was released from U.S. custody at Guantanamo Bay a year ago. The other commanders were named as Mullah Haji Amir and Tohr Mullah Maqid.

U.S. officials had no immediate comment.

Pashtun said there were "big commanders" also among 40 suspected Taliban detained in an operation by some 300 Afghan soldiers in three other districts of Kandahar.

Meanwhile, U.S. and Afghan forces pursuing terror suspects in Paktika province crossed for several hours into neighboring Pakistan but made no arrests before coming back to Afghanistan, residents and Pakistani defense officials said.

A Pakistani defense official, speaking on condition of anonymity, said that the Foreign Ministry would be urged to complain to U.S. authorities. Pakistan has refused to grant U.S. troops the right to pursue guerrillas in its territory.

U.S. officials had no immediate comment.

In the normally peaceful province of Farah, near the Iranian border, gunmen killed two officers Wednesday as they returned from escorting U.N. staff, Farah Gov. Abdul Hay Nayiamati said.

More than 300 people have died in violence across Afghanistan this year, casting doubt on the country's readiness to hold elections in September and underlining the difficulty faced by U.S.-led forces trying to subdue militants operating across the south and east.