Abu Zubaydah was drawn to Usama bin Laden's organization as a teen-ager whose religious fervor and radical Islamic ideology brought him to the training camps of Afghanistan.

But Middle East counterterrorism sources say it was his combat skills and organizational talent that pushed him to the top ranks of the network thought to have been behind the Sept. 11 terrorist attacks on the United States.

U.S. military and law enforcement officials said that Abu Zubaydah, a 31-year-old Palestinian, was captured in Pakistan four days ago — an arrest touted by White House officials as a "very serious blow" to the Al Qaeda network.

Born Zein al-Abedeen Mohammad Hassan, his family hails from the Gaza Strip and according to Jordanian court records, he holds an Egyptian travel document. Egypt, which once ruled the Gaza Strip, used to issue travel documents to residents there. But Egyptian Interior Ministry officials said they had no record for Abu Zubaydah and that his Egyptian travel document could be fake.

After Sept. 11, the U.S. Treasury Department ordered frozen any assets found in his name. It's website, lists Abu Zubaydah's birthplace as Riyadh, Saudi Arabia and his birthdate as March 12, 1971.

Last Thursday, Pakistani authorities, in concert with the CIA and FBI, captured Abu Zubaydah in a raid in Faisalabad, far from the Afghan border, according to U.S. officials who spoke on condition of anonymity. Abu Zubaydah was shot three times trying to escape — in the stomach, groin and leg — but was expected to survive, said one official.

He is in U.S. custody, and American officials promised a lengthy interrogation of the man believed to be able to identify names, faces and locations of Al Qaeda operatives the world over.

U.S. officials would not say where he was being held. But they did say he was not expected in the United States any time soon. He could eventually be held in Afghanistan, aboard a Navy ship, at the U.S. base in Guantanamo Bay, Cuba, or transferred to a third country.

According to the Middle East sources, who insisted they not be identified further, Abu Zubaydah developed a unique talent in mortars and other heavy weaponry that attracted the attention of bin Laden.

He was apparently named bin Laden's second deputy in 1995, responsible for screening recruits and devising terrorist plans. Where bin Laden and deputy Ayman al-Zawahri would set policy, Abu Zubaydah would implement it. U.S. officials said when the inner circle would order the bombing of an embassy, Abu Zubaydah would select the embassy, cell and method of attack.

Abu Zubaydah's name doesn't appear on the FBI's list of top wanted terrorists but he was wanted nonetheless.

The job description and slot at the top led U.S. officials to worry that Abu Zubaydah may try to re-establish Al Qaeda in Pakistan, where many members fled the U.S.-led military campaign in Afghanistan. Financial transfers and intercepted communications suggested he was directing attempts to conduct new terrorist attacks against U.S. interests, American officials have said.

Ahmed Ressam, convicted April 2001 of smuggling, terrorist conspiracy and other charges in the Los Angeles millennium plot, described Abu Zubaydah's role as a recruiter during court testimony.

"He is the person in charge of the camps. He receives young men from all countries. He accepts you or rejects you. And he takes care of the expenses for the camps. He makes arrangements for you when you travel coming in or leaving," Ressam said.

Prospective recruits in Pakistan would meet Abu Zubaydah, who would assign them to camps. When they finished training, he placed them in cells overseas.

According to Jordanian military documents, Abu Zubaydah recruited Raed Hijazi, a Jordanian-American who worked as a taxi driver in Boston and used his pay to buy arms for the Jordanian cell. He has also been named as a recruiter of suspects in plots to bomb U.S. Embassies in Paris and Sarajevo.

Intelligence and police officials have linked him to at least five Al Qaeda plots, including the attacks on the World Trade Center and Pentagon. The extent of his role, however, has not been fully determined.

He is believed to have been a field commander for the October 2000 bombing of the USS Cole in Yemen, in which 17 U.S. sailors were killed and the foiled millennium plots in Los Angeles and Jordan. Middle East sources said Abu Zubaydah helped set up the terrorist cell in Jordan charged with carrying out the millennium plot to attack American and Israeli targets, and was in constant touch with Khader Abu-Hosher, a Palestinian recruiter with the cell.

The two men discussed the plot in a 1999 phone call, according to the Jordanian documents.

But Jordanian intelligence, already tipped to Abu-Hosher and 16 other members of his group, had been listening to his calls. They raided the group's homes in a sweep on Nov. 30, 1999 where they found fake passports, manuals and maps of tourist targets in Jordan, including hotels and a site on the Jordan River where Jesus Christ was believed to have been baptized.

In September 2000, a military court sentenced Abu-Hosher to death. Abu Zubaydah, who was at large, was found guilty of conspiracy to carry out terror attacks in Jordan. He was sentenced in absentia to 15 years of hard labor.