Pakistan has handed over a suspect in the U.S. embassy bombings to Kenyan officials in Nairobi, where a growing team of FBI investigators pressed ahead Sunday in its search for new evidence.

The Pakistan Foreign Ministry and another government source said Sunday that Mohammad Sadik Howaida was sent to Kenyan authorities last week, bypassing U.S. investigators who had flown to Pakistan to question him. The private television network KTN reported that Howaida had arrived Sunday, without citing a source.Pakistani newspapers reported that in recent interrogations, Howaida had confessed to being involved in the Nairobi bombing and had outlined a plan that included co-conspirators.

A ministry spokesman said Howaida was arrested upon arriving at Karachi airport from Nairobi on Aug. 7, the day that twin bombings at the U.S. embassies in Nairobi and Dar es Salaam, Tanzania, killed 257 people and wounded at least 5,500 others.

U.S. officials in Nairobi refused to discuss Howaida. "This is a matter in which we are working very closely and very hard with our Kenyan colleagues. I can't make any comment," said Hardrick Crawford, the assistant FBI special agent in charge of the Nairobi investigation. "This is an ongoing investigation."

The U.S. Embassy in Islamabad also refused comment.

As the probe in Nairobi intensifies, more FBI agents arrived over the weekend in the Kenyan capital, where they are expected to stay for four to five months.

Newsweek reported that investigators have found a 100-pound steel drive shaft believed to have belonged to the pickup truck that carried the bomb to the embassy in Nairobi. The shaft, found more than a half-mile from the site, contains part of the vehicle identification number, the magazine said in this week's issue, quoting unidentified sources.

FBI spokeswoman Debbie

Weierman, speaking in Washington, would not comment on the report.

In a show of support for both East Africans and embassy staffers abroad, Secretary of State Madeleine Albright is planning brief stops in Dar es Salaam and Nairobi on Tuesday.

The government source in Pakistan said the suspect told his interrogators that other conspirators had left Nairobi earlier and had already passed through Pakistan into Afghanistan. He had planned to do the same, the source said.

The source told The Associated Press that investigators suspected a link between Howaida and exiled Saudi multimillionaire Osama bin Laden, who has been living in Afghanistan for the last two years.

U.S. officials have said that bin Laden, who has been vocal in his hatred of the United States and is among the world's most militant sponsors of terrorism, was a possible suspect in the African bombings.

A Kenyan guard at the U.S. Embassy in Nairobi identified a photograph shown to him by the FBI as someone he had seen at the bombing, a U.S. official who spoke on condition of anonymity said. The official would not identify the person in the photograph. But Knight Ridder News Service and Newsday have reported he was an associate of bin Laden.

Pakistani Foreign Ministry spokesman Tariq Altaf said immigration officials determined that Howaida's Yemeni passport was forged, and he was questioned extensively by Pakistani officials.

"On satisfaction about his involvement in these terrorist acts, he was sent back to Nairobi and handed over to the Kenyan authorities for appropriate action under their law," Altaf said, adding that Howaida was sent to Nairobi aboard a special plane.

A ministry statement identified Howaida as an "Arab national" without elaboration.

On Saturday, U.S. authorities in Washington said CIA agents were headed to Pakistan to question him. But Altaf said no foreigners were allowed to interrogate Howaida. The government source said U.S. officials who came to Karachi were refused access to Howaida by the Pakistani government, and had to follow him to Kenya on another plane.

It wasn't clear why Howaida was not directly handed over to the Americans. But it could be fallout from the case involving Mir Aimal Kasi, a Pakistani convicted in the United States of killing two CIA employees during a shooting spree in Virginia in 1993.