Key bin Laden lieutenant 'captured' in Pakistan

The raids were conducted under heavy security and with the reported aid of U.S. operatives.

ISLAMABAD, Pakistan (CNN) -- A Pakistani government source said the most senior al Qaeda member captured since the September 11 attacks is in custody in Pakistan.

Abu Zubaydah -- a 30-year-old Palestinian believed to be operational commander of al Qaeda -- was captured after a series of raids on suspected al Qaeda and Taliban hideouts late last week in locations including Lahore and Faisalabad, the source said on Monday.

Zubaydah is believed to be among more than 50 people taken into custody in raids that netted Pakistanis, Afghans and suspects of other national origins, the source added

In the past, U.S. officials have described Zubaydah as one of Osama bin Laden's key lieutenants, well connected with terrorist sleeper cells around the world, who may seek to organize additional attacks against U.S. targets.

His full name is Zayn al-Abidn Muhammed Hasayn Abu Zubaydah.

Born in Saudi Arabia, he speaks English and is considered an expert at disguises, skilled at remaining out of sight for years at a time.

'Very senior'

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On Saturday, a senior Bush administration official with knowledge of intelligence matters said "the U.S. strongly suspects they've captured someone very senior in al Qaeda," but authorities are not positive of the person's identity.

Meanwhile, a regional intelligence source confirmed to CNN there are extensive efforts underway to determine the identities of those being held.

It is too early, the source said, for authorities to be able to positively identify all those in custody.

The raids early Thursday took place under extremely tight security.

Raids

A Pakistani police spokesman said the suspects opened fire during one of the raids, seriously wounding an officer.

One of the suspects was killed, the spokesman said, and two more wounded.

About 35 Americans joined the Pakistani police in the operation, police sources said, but it was not clear where the operatives came from.

The U.S. military said Friday that its personnel did not take part. Officials in the U.S. Justice Department declined to comment.

The Pakistani spokesman also said authorities conducted the raids after getting unspecified information that the suspects had been "involved in terrorist activities in the past and were planning further terrorist acts."

Pakistani President Pervez Musharraf banned five Islamic groups in January as part of a major crackdown on militancy in his country.

-- Islamabad Bureau Chief Ash-Har Quraishi, CNN State Department Correspondent Andrea Koppel, and Senior International Correspondent Sheila MacVicar contributed to this report.