-- Khalid Sheik Mohammed, the al Qaeda lieutenant alleged to have organized the Sept. 11, 2001, terrorist attacks on the United States, was captured today by U.S. and Pakistani intelligence agents in the Pakistani city of Rawalpindi, officials said.

Mohammed was apprehended in a predawn raid on a house in Rawalpindi's posh Westridge district, along with two other suspected al Qaeda members whom authorities identified as a Pakistani and an Arab. Within hours, Gen. Pervez Musharraf, Pakistan's president, authorized the transfer of Mohammed and the Arab suspect to a U.S. detention center at an undisclosed location "outside Pakistan," a senior Pakistani intelligence official said.

"According to the standard procedure, the rendition of non-Pakistani suspects to the U.S. authorities was completed by Saturday evening," said a Pakistani official. "The Pakistani suspect will be prosecuted here."

Mohammed, described by intelligence officials and analysts as the principal planner of operations for Osama bin Laden's al Qaeda network, is believed to be the highest-ranking al Qaeda leader captured in the U.S.-led hunt for members of the organization. Though he has not been charged in connection with the suicide attacks on the World Trade Center and the Pentagon, evidence of his involvement includes a radio interview conducted in December in which Mohammed said he was the mastermind of the attack.

In addition, he has been under indictment since 1996 in connection with a plot to blow up U.S. airliners over the Pacific Ocean. In warnings last month that al Qaeda was planning terrorist attacks inside the United States, U.S. officials said Mohammed appeared to be the planner.

The capture of Mohammed was hailed by White House press secretary Ari Fleischer as "a wonderful blow to inflict on al Qaeda." A statement issued by Fleischer's office called Mohammed one of bin Laden's "most senior and significant lieutenants, a key al Qaeda planner and the mastermind of the September 11th attacks."

Mohammed has also been mentioned in connection with the kidnapping and subsequent murder of an American journalist, Wall Street Journal reporter Daniel Pearl, a year ago. "I am sure this will be on top of the FBI agenda when they start quizzing Khalid Sheik from tomorrow," said a Karachi police official who had been coordinating with the FBI in the Pearl investigation.

Informed Pakistani officials said tonight that word of Mohammed's presence in Rawalpindi, where the Pakistani military has its headquarters, was passed to them this week by U.S. intelligence officials in Islamabad, the capital. Mohammed had been hiding since January in the house of a Pakistani identified as Abdul Qudoos Khan, according to authorities. Khan, who was the Pakistani captured with Mohammed, was an active member of Pakistan's largest religious party, Jamaat-e-Islami, officials said.

Agents from both countries coordinated the raid, but U.S. agents were not on the scene when police moved on Mohammed at about 4 a.m., according to Pakistani sources.

In contrast, FBI and CIA agents were close at hand during the capture last year of other key al Qaeda suspects in Pakistan, including Abu Zubaidah in Faisalabad and Ramzi Binalshibh in Karachi. But resentment among radical Muslims in Pakistan, which has been simmering since Musharraf vowed to support U.S. anti-terrorist operations after Sept. 11, is particularly high as the United States threatens war against Iraq, officials here said.

Sources said two shots were fired from inside the house as officers approached but that the suspects quickly surrendered. Police searched the house for an hour and removed documents, a desktop computer and computer disks, according to witnesses.

Pakistani intelligence officials said that FBI agents identified Mohammed shortly after his capture. "We had limited information on Mohammed. In fact, we didn't have any of his recent pictures," said an informed Pakistani official.

The capture of Mohammed came one day after gunmen killed two Pakistani police officers outside the U.S. Consulate in Karachi. Senior Karachi police officials said today that a suspect arrested soon after the shooting said during interrogation that the attack was planned by unidentified al Qaeda operatives in Karachi. The man was identified as Zulfiqar Ali, 25, a Karachi factory worker.

"He is an al Qaeda foot soldier," said an official familiar with Ali's interrogation. "He was hired by an Arab and a Pakistani religious militant at a local mosque to attack the guardians to American interests in Pakistan."

Westridge, the Rawalpindi neighborhood where today's raid was conducted, is a residential and office district a five-minute drive from Pakistani army headquarters. Several military departments have their offices in the district, and many of its residents are retired senior military officials. Tonight officials speculated that Mohammed chose the neighborhood because it was an unlikely place for a wanted terrorist to hide.

Residents who witnessed the raid told reporters that they were surprised because they had never seen any suspicious activities at Khan's residence, which was often used for meetings by local Jamaat-e-Islami leaders. Considered the best-organized political party in Pakistan, Jamaat is part of a coalition of religious parties that forms the third-largest bloc in parliament and is not considered to be radical.

However, two active supporters of Jamaat were arrested in Lahore in December and charged last month with providing shelter and medical care to fugitive al Qaeda members, according to senior Pakistani intelligence sources. In January, two alleged al Qaeda members were arrested at a house owned by an active Jamaat member in the western suburbs of Karachi.

A relative of Abdul Qudoos Khan points to the disarray in Khan's Rawalpindi home following the raid that yielded Khalid Sheik Mohammed.