New terrorism charges have been filed against a Nigerian man accused of trying to detonate explosives aboard a U.S.-bound airliner on Christmas Day last year.
A grand jury in the state of Michigan Wednesday charged 24-year-old Umar Farouk Abdulmutallab with a new count of conspiracy to commit terrorism. It alleges he acted with others, both known and unknown to the grand jury, to carry out the al-Qaida plot.
He is expected to be arraigned in a Detroit federal court Thursday.
Earlier this year, Abdulmutallab pleaded not guilty to six criminal counts, including attempted use of a weapon of mass destruction and attempted murder. Prosecutors say he tried to detonate explosives concealed in his underwear during the flight from Amsterdam to Detroit.
Earlier this year, the U.S. television network CBS reported that Abdulmutallab boasted during his interrogation that some 20 other young Muslim men were being trained in Yemen to carry out similar attacks.
Abdulmutallab's name had been included in a broad database of individuals who are suspected of having some link to terrorism. But he was not on higher-profile watch lists that might have caught the attention of security screeners.