The Nigerian man accused of trying to blow up a U.S. passenger plane on Christmas Day 2009 has been sentenced to life in prison.

Umar Farouk Abdulmutallab was sentenced Thursday in the U.S. city of Detroit.

He pleaded guilty in October, as his trial was getting underway. He had told the court his actions were in retaliation for the killing of what he called innocent Muslims in Yemen, Afghanistan and elsewhere.

Prosecutors say Abdulmutallab wanted to achieve martyrdom and was on the Northwest Airlines flight for one reason — to kill all 290 people on board as part of an al-Qaida mission.

Passengers and crew members subdued Abdulmutallab after he tried to detonate the explosives in his underwear as the plane prepared to land in Detroit. The explosives caught fire, leaving him with severe burns.

The charges against him included conspiracy to commit terrorism and attempted use of a weapon of mass destruction for trying to bring down the flight from Amsterdam on December 25, 2009.

Abdulmutallab had made several outbursts during jury selection, proclaiming allegiance to al-Qaida and claiming that Yemen-based radical cleric Anwar al-Awlaki is still alive. The American-born Awlaki was killed last year in Yemen by a U.S. airstrike.

U.S. officials have blamed Abdulmatallab's plot on the Yemen-based branch of al-Qaida.