Nigerian ‘underwear bomber’ sentenced to life

25-year-old student, Umar Farouk Abdulmatuallab concealed a bomb in his underwear, which caused a fire aboard the Delta Airlines flight on Christmas Day 2009, but failed to explode.

Abdulmutallab was eventually overpowered by some of the 289 passengers and crew on the Northwest Airlines flight 253 from Amsterdam to Detroit.

The attack caused the US to tighten up both its 'no-fly' lists and airport security.

The would-be suicide bomber said he was carrying out the work of God against the "oppressors" of Muslims and was given the maximum sentence.

Abdulmutallab , who pleaded guilty, said his plan was to avenge "the attacks of the United States on Muslims."

The Nigerian became radicalised during a series of trips to Yemen where he met the cleric Anwar al Awlaki , part of al Qaeda's Yemen-based wing.

He travelled to Yemen in 2004 where he enrolled at the Sanaa Institute for Arabic Language.

A former teacher said Abdulmutallab was not deeply religious when he arrived in Yemen in 2004 but became a devoted follower of Islam.

Abdulmutallab stayed in Yemen for a year between 2004 to 2005, before returning for another stay from 4 August to 21 September in 2009.

He claimed he stayed with Awlaqi and spent two weeks preparing at a training camp where he "received instruction in weapons and indoctrination in jihad".