On Assignment: Tora Bora Manhunt

Afghan anti-Taliban fighters examine munition boxes in al Qaida cave bunker, Milawa Valley, Tora Bora White Mountains, Afghanistan.
CBS News National Security Correspondent David Martin traveled with U.S. special forces scouring the cave complexes at Tora Bora mountain in Afghanistan last week.

At an abandoned schoolhouse deep in the Tora Bora mountains waits an unlikely looking group of American soldiers. They are U.S. special forces, working under the command of an American in charge of searching for the caves of Tora Bora.

"We want to ensure that they are clear of any Taliban or al-Qaida forces and exploit any documents or equipment that would be in those sites," said a U.S. army major. CBS News has agreed not to use the soldiers' names or show clear pictures of their faces.

But the search for the caves is proving as frustrating as the hunt for Osama bin Laden himself.

"What surprised us the most is the absence of cave sites. We came in with the clear intention to come in and go from cave site to cave site and find a vast amount of information. And so far we've found there's only a few cave sites," he said.

The special forces have given up any real hope of finding bin Laden in Tora Bora. But they are convinced he was in this area, probably living in huts they've come across and using a nearby cave as a bomb shelter.

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about the hideouts in Tora Bora.

Bin Laden's trail grows cold in this small valley. It's where he was last reported seen, during the bombing of Tora Bora on Nov. 29.

None of the nearby cave entrances lead to the vast, multi-level underground complexes bin Laden was said to have built in Tora Bora. These caves really are just caves, where al-Qaida fighters took shelter and stored their ammunition. You have to make a steep breathless climb up to the ridge above to get to their fighting positions.

One al-Qaida observation post here could command a field of fire of from two to three miles. But an American plane came along and laid down a stick of bombs, creating a string of craters in the terrain.

For all the devastation, there is no sign of bodies. The al-Qaida fighters are either dead and buried or fled deeper into the mountains. The caves themselves appear to be largely untouched by all those airstrikes.

"The air had no effect on the caves other than, you know, putting debris over the entrances. You walk in the cave and the inside of it, the structure, wasn't affected whatsoever," said one soldier.

One cave complex did yield a garbage bag full of propaganda pamphlets, maps, letters, and identification papers.

On Thursday's CBS Evening News, the special forces set out by mule train in search of another al-Qaida hideout, this one high in mountains.

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