The walls may be closing in on Usama bin Laden after the capture of one of his most trusted lieutenants, but the world's most wanted man has survived a lifetime of close calls, and has made narrow escapes his calling card. Will this time be any different?

Intelligence agencies are acting on a trove of information found during the March 1 arrest of alleged Al Qaeda No. 3 Khalid Shaikh Mohammed. Pakistani military sources have told The Associated Press that U.S and Pakistani intelligence have narrowed the search for bin Laden to a remote 350-mile corridor from the southwestern Pakistani town of Chaman to the Afghan-Iranian border.

Former Taliban and Taliban in hiding have told The AP that bin Laden is constantly on the move, usually with an entourage of less than 10 people, and there were reports Friday - denied by senior Pakistani and U.S. officials - that at least one of his sons was captured.

But officials and counterterrorism experts say it may be premature to count out the billionaire fugitive. The U.S. military has not confirmed any operations in the corridor, and even if bin Laden is in the region, catching him will be a formidable task.

"He's a single individual who has a lot of money at his disposal, and a network of people who work with him and for him and who are willing to go out on a limb to hide him," Col. Roger King, a spokesman for the U.S. military at Bagram Air Base, near the Afghan capital Kabul, said Saturday. "Certainly, that makes it a challenge to catch him."

Bin Laden apparently escaped an international dragnet at least three times before.

In December 2001, U.S. and Afghan troops surrounded a giant cave complex in the eastern Afghan region of Tora Bora, and on Dec. 10 intercepted a radio transmission that was believed to have come from the Al Qaeda leader.

U.S. warplanes blanketed the area with bombs, but the Americans relied largely on local Afghan forces on the ground. Hundreds of Al Qaeda suspects are believed to have escaped across the border into Pakistan, and bin Laden may have been among them.

Intelligence officials believe bin Laden has been hiding in the mountains between the two countries ever since. He has not been seen since a November 2001 videotape, but several audiotapes reputedly made by the terror chief have been released in recent months.

In August 1998, the Clinton Administration ordered a cruise missile strike on two of bin Laden's terrorist training camps in Afghanistan after Al Qaeda orchestrated the bombings of two U.S. embassies in Africa. Bin Laden is believed to have been at the Zhawar Kili Al-Badr camp for a meeting with several of his top men, but left shortly before some 70 Tomahawk cruise missiles slammed into the dusty complex.

Bin Laden could have been caught in Sudan in 1996, before the October 2000 bombing of the USS Cole, the Africa embassy bombings and the Sept. 11 attacks.

Clinton administration officials have told The Associated Press they tried to convince authorities in bin Laden's native Saudi Arabia to allow Sudan to deport him for trial there. But the Saudis refused, fearing a trial would destabilize the country, the officials said on condition of anonymity. In May of that year he fled to Afghanistan.

The near misses have given bin Laden an aura of invincibility among his supporters, but that could be fading under the pressure of the biggest manhunt in history.

Bin Laden's Taliban protectors are gone, and top confidantes like Mohammed and former al-Qaida leader Abu Zubaydah are in U.S. custody. Mohammed Atef, Al Qaeda's military chief, was killed in the U.S. bombing that ousted the Taliban, and another top Al Qaeda operative was killed in Yemen in November when an unmanned U.S. Predator drone fired a missile at his car.

"The people who have been helping him stay elusive are getting captured or killed, so the chances of him getting caught now are much brighter than they were six months ago," said security analyst Talat Massood, a retired Pakistani general. "Bin Laden has shown many times that he has the capacity to survive, but conditions are not favorable for him now. The noose is tightening."

Michael Swetnam, a counterterrorism specialist at the Washington-based Potomac Institute for Policy Studies, said the United States is trying to act faster on information like that obtained in the Mohammed arrest. He said bin Laden has forced the change because of his ability to anticipate American intelligence.

"It really is a chess game. He has escaped two or three times before, mostly because he has been a real student of our operational process," said Swetnam. "He slips through the cracks because he knows where the cracks are."