Islamabad, Pakistan ? The walls may be closing in on Osama bin Laden after the capture of one of his most trusted lieutenants, but the world’s most wanted man 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-Qaida 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.

A Pakistani man drives his water tanker decorated with posters of Osama bin Laden in Chaman, Pakistan, a border post between Pakistan and Afghanistan. Pakistani authorities have increased security along the borders to watch for fleeing al-Qaida and Taliban members after authorities arrested suspected Sept. 11 mastermind Khalid Shaikh Mohammed.

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-Qaida leader.

U.S. warplanes blanketed the area with bombs, but the Americans relied largely on local Afghan forces on the ground. Hundreds of al-Qaida 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-Qaida 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 also escaped capture in Sudan in 1996, before the October 2000 bombing of the USS Cole, the Africa embassy bombings and the Sept. 11 attacks.