Bagram, Afghanistan ? U.S. troops hauled bags of documents Saturday from abandoned al-Qaida and Taliban caves to Bagram air base after days of searching through mountains, turning up secret jail cells and dossiers with photographs and fingerprint samples.

Some 500 U.S. troops spent the past five days going inch by inch through the caves in the Zhawar Mountains of Paktia province near the Pakistani border, then blowing up the caverns after stripping them down in a mission dubbed Operation Mountain Lion.

A soldier from the American 101st Airborne Division keeps guard inside a man-made cave in the Zhawar Kili mountain complex, Paktia province, eastern Afghanistan. The soldier, pictured Tuesday, was taking part in the Operation Mountain Lion.

“The locals were saying these were the caves where Osama bin Laden was” sometime in the past, said Capt. Lou Bauer, 29, of Windsor, N.Y., who was among a group of soldiers who returned Saturday to Bagram airbase in Chinook helicopters. “We were destroying munitions and felt like we were doing something important.”

U.S. and other allied special forces units have been in the Paktia province area occasionally in recent months, identifying cave hide-outs and looking for intelligence to use in the hunt for al-Qaida and Taliban forces.

Intelligence gathered there and during Operation Anaconda, a large assault last month on al-Qaida caves nearby led planners to decide to send a larger force for a thorough search.

“A battalion of 500 searching is different from a few people, so we thought from the intelligence and evidence we saw it was worthwhile for us to go back again,” Maj. Bryan Hilferty, a U.S. military spokesman at Bagram, said.

The mission took troops through a dry, narrow valley resembling a creek bed between two mountains. The caves, some well-hidden and others with entries like small Roman arches, opened onto the valley. The narrow pass is a road for some locals, and soldiers described seeing sporadic traffic of people, camels, sheep and one truck.

Troops searched and destroyed some 15 caves. Built into mountainsides, the caverns were interconnected. Bauer drew a map that went on for three pages, showing how one cave went some 1,000 feet deep.

Army engineers used C-4 explosives to collapse the caves some of which were fortified with brick walls, steel beams and reinforced ceilings after other methods failed, Bauer said.

The searches netted five trash bags full of documents, including folders that looked like dossiers, with photos and fingerprint samples attached. Soldiers also found medical supplies, including syringes and antibiotics; rocket-propelled grenades; and, deep inside one cave, three cells with bars. It was not immediately clear what the cells were used for.

They also found a May 17, 2001, edition of USA Today.

Hilferty would not comment on what the documents said or the value of the other information found, but said, “Everything that we find is significant.”

An Associated Press photographer heard an Afghan soldier tell an American officer that some 800 al-Qaida and Taliban fighters had regrouped a few miles away, just over the border in Pakistan. The soldier, translating for his commander, complained that “the Pakistanis aren’t doing anything about it.”