U.S. forces on a sweep in southeastern Afghanistan detained one man and found documents in his vehicle with potential intelligence value, a U.S. military spokesman said Thursday.

The sweep that began this week is the latest military operation in southeast Afghanistan near the Pakistan border, where remnants of the Taliban and Al Qaeda are suspected to be sheltering in the mountains and where rivalry between warlords threatens Afghanistan's security.

Col. Roger King, a spokesman at the main U.S. base at Bagram, did not give details of why the documents seized Wednesday were suspected of having intelligence value. The seizure was made when U.S. forces detained a man at a roadblock.

He also said that the large weapons cache found in a cave on Wednesday will be evaluated and that if the weapons are found to be usable they may be given over to Afghanistan's fledgling national army.

The cache, found Wednesday in the town of Nariza in Paktia province, included 400 rocket-propelled grenades, 20 cases of land mines and a large quantity of machine-gun ammunition, King said.

Also Thursday, the military said a team looking into an American airstrike that killed civilians has returned to Bagram after touring damaged villages and interviewing U.S. forces involved in the July 1 attack, which Afghans say killed 48 people and wounded 117.

U.S. officials say they believe civilians were killed, but have not said how many. Afghans say 25 of the dead were celebrating a wedding party when an American AC-130 gunship fired on villages in Uruzgan. U.S. officials say the attack was provoked by persistent anti-aircraft fire from sites in the villages, many of which were battered in the raid.

The investigators interviewed U.S. forces at the Khanabad air base in Uzbekistan, in Bagram and in the southern city of Kandahar. They visited damaged villages in Uruzgan province on Wednesday with some Afghan military officials and the governor of the province, Jan Mohammed Khan, King said.

"They are now evaluating the information," King said, without saying when a final report might be released. U.S. officials have not said which American units were involved in the air strike.