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By Kristin Roberts

WASHINGTON, March 26 (Reuters) - Kenya has handed over an al Qaeda suspect accused in two terror attacks in East Africa to U.S. authorities who have moved him into the Guantanamo Bay military prison, officials said on Monday.

Pentagon spokesman Bryan Whitman said Abdul Malik admitted involvement in a 2002 attack on a hotel in Mombasa, Kenya, that killed more than a dozen people and an attempt to shoot down an Israeli airliner carrying 271 passengers near Mombasa.

"Due to the significant threat this terror suspect represents, he has been transferred to Guantanamo," Whitman told reporters.

A senior defense official, speaking on condition of anonymity, said Kenyan authorities had offered Malik to the United States.

Malik is the first detainee to be sent to Guantanamo since September 2006, when 14 al Qaeda suspects considered by the Pentagon to be "high-value" detainees arrived from secret CIA prisons overseas, Whitman said.

Before that there had been no detainee transfers into Guantanamo since September 2004.

Whitman called Malik "dangerous," but did not characterize him as "high-value." U.S. officials use that designation when a detainee's capture is believed to have had a significant effect on al Qaeda operations and when the detainee is believed capable of providing high-quality intelligence.

"He is a one of these support figures in the al Qaeda East Africa network. He knows some very important people," said another American official, speaking on condition of anonymity.

Kenya has rounded up scores of suspected Islamist fighters and supporters since a war ended a six-month Islamist rule of Mogadishu and south Somalia.

U.S. officials would not say if Malik was among the fighters flushed out of Somalia. But he is suspected of association with at least one al Qaeda suspect believed by U.S. officials to be hiding among fleeing Islamist troops.

That suspect, Kenyan Saleh Ali Saleh Nabhan, is wanted in connection with the 2002 Mombasa hotel bombing that U.S. officials blame partly on Malik.

After Malik's transfer from Kenyan custody, he was held at an American military facility, interviewed by U.S. law enforcement and then sent to the military prison at Guantanamo Bay over the weekend, according to the senior defense official. The official said Malik was not held in any secret CIA prison.

The Pentagon would not provide the nationality of the suspect.

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