Investigators shed light on foiled Christmas terror attack

BEIJING, Dec. 29 (Xinhuanet)-- In search for clues to the foiled Christmas Day bombing of a U.S.-bound plane, part of an explosive device was found sewn into the underwear of the Nigerian suspect, according to media reports quoting a U.S. law enforcement official on Monday.

A slightly charred and singed underpants with the explosive packet  removed from the crotch is seen in government photos obtained  exclusively by ABC News, released to Reuters, December 28, 2009. (Xinhua/Reuters Photo)

The U.S. security authorities have focused their investigation on how AbdulMutallab, 23, smuggled the explosives aboard the flight.

AbdulMutallab's trip originated in Lagos, Nigeria. There, he did not check in a bag as he flew on a KLM flight to Amsterdam, said Harold Demuren, director-general of Nigeria's Civil Aviation Authority.

Demuren said the suspect underwent regular screening -- walking through a metal detector and having his shoulder bag scanned through an X-ray machine. He then underwent secondary screening at the boarding gate for the KLM flight, according to officials of the Dutch airline.

After arriving in Amsterdam, AbdulMutallab boarded the Northwest Airlines flight to the United States.

According to the Netherlands' national coordinator for counterterrorism, AbdulMutallab had gone through "normal security procedures" before boarding the flight to Detroit.

AbdulMutallab, who had a multiple-entry visa to the United States, was in Yemen between August and December.

Relatives of the suspect said Monday that they told authorities weeks ago about AbdulMutallab's abnormal behavior. AbdulMutallab was studying abroad when he "disappeared" and stopped communicating with his relatives.

His father, Umaru AbdulMutallab, contacted Nigerian security agencies two months ago and foreign security agencies six weeks ago.