Nigerian's trips may offer clue to U.S. attack plot

Umar Farouk Abdulmutallab in an undated booking photo.

LONDON (Reuters) - Studying in Yemen, the reserved Nigerian aroused the curiosity of housemates, prompting one to ask why the young man "excused himself from our revelries, our late night meals, our conversations 'till all hours."

"Then one day, early this October, we noticed his room was emptied. I never thought to question it much, as he had mentioned returning home at some point," the housemate, Matthew Salmon, a Canadian fellow student of Arabic, wrote in a blog.

But instead of going home, the quietly spoken Nigerian, Umar Farouk Abdulmutallab, had vanished into the countryside to visit al Qaeda leaders before leaving Yemen on a journey that investigators say ended with him attempting to blow up a U.S. airliner over Detroit.

The investigators are examining the 23-year-old's roundabout route to Detroit via the Middle East, Africa and Europe and the people he met on his journey for clues to one of the worst U.S. security breaches since the September 11, 2001 attacks.

Abdulmutallab is believed to have visited or been in transit through five countries in the two weeks before boarding a U.S.-bound flight on December 25, capping four years as an expatriate student spent variously in Britain, the United Arab Emirates and Yemen.

The son of a wealthy Nigerian banker, Abdulmutallab was seized after failing to properly detonate a bomb on an airliner as it approached Detroit. Under questioning in the United States, Abdulmutallab said al Qaeda in Yemen had supplied him with the device and trained him in how to detonate it, a U.S. official said.

Counter-terrorism officials are looking at his December trips, his travels in preceding years and changes in his character and ideas to try to learn the extent of his ties to al Qaeda, which has claimed the failed attack, and gauge its ability to attempt more such strikes.

Among investigators' top questions are:

-- Where did he obtain the bomb?

-- Was he helped by accomplices on his December journey from Yemen to Ethiopia, Ghana, Nigeria and the Netherlands?

-- What did he do when he went missing for several weeks in Yemen?

-- Were there earlier attempts by al Qaeda to test the kind of device he eventually sought to use?

One conundrum has been the sheer number of December flights.

BORDERING ON RECKLESSNESS

Assuming Abdulmutallab really was given the explosives in Yemen, on the face of it his busy itinerary appears to signal a boldness bordering on recklessness, some experts say.

This is because the more air journeys a suicide bomber attacker takes prior to boarding a plane targeted for attack, the more often he or she must go through security checkpoints, and the greater likelihood of the explosives being discovered.

Aviation analysts say that no security technology widely deployed at international airports at present is able to detect the materials he was carrying sewn into his underwear.

"He could have taken 100 flights without being found out," aviation security expert Philip Baum said.

"The only chance would be a close physical examination of him. No one did that."

Still, the number of flights intrigues many observers.

Some see in his busy December itinerary an attempt to cover his tracks, putting time and distance between his presence in Yemen, a known security hotspot, and his destination. This might have reduced the chance U.S. homeland security officials would spot the Yemen connection and bar him from the December 25 flight.

COUNSEL FOR LONELINESS

Another possible explanation is that he was seeing an accomplice somewhere in Africa who supplied him with the bomb.

Investigators also are examining two incidents that some see as possible test runs for the December 25 attack.

On August 27, Abdullah al-Asiri, a 23-year-old suicide bomber posing as a repentant militant, tried to kill Prince Mohammed bin Nayef who heads Saudi Arabia's anti-terrorism campaign. Asiri also was working for al Qaeda's Yemen branch.

On November 13, police in Mogadishu arrested a young Somali man attempting to board a Dubai-bound plane with a suspicious white powder, liquid and syringes. After the December 25 attack, Western security experts have sought to examine the incident to evaluate possible similarities with the Detroit attack.

Abdulmutallab had years as an expatriate student variously in Britain, the United Arab Emirates and Yemen and his evolving state of mind during this time is a focus of the investigation.

A teacher who taught Abdulmutallab in Yemen said he was "closer to being secular" on a first visit in 2004-05 but on his second visit in 2009 "was more committed to praying and Islam."

A Washington Post review of 300 postings by him between 2005 and 2007 showed that the son of a wealthy banker sought counsel for loneliness, marriage and on matters of his Muslim faith.

(Editing by Michael Roddy)