Brits Hunt for Northwest Bomber's Cohorts Officials fear he plotted with extremists in London By Mary Papenfuss, Newser User Posted Dec 28, 2009 2:13 AM CST 5 comments Comments Umar Farouk Abdul Mutallab poses in a snapshot with a woman believed to be a family member. (AP) (Newser) – British officials are hunting for possible accomplices of the Nigerian whose attempt to ignite a bomb on a Northwest flight to Detroit was thwarted by passengers. Umar Farouk Abdulmutallab, 23, attended a London university for three years, and security officials fear he may have been plotting a terror attack with other extremists during that time. Officials suspect he planned to launch an attack in Britain but had to change plans after he was denied a student visa to return to London. "We are now going back through our work to see if he may have been on the periphery of another group or trying to contact radicals in this country," said a source. Security agencies in both Britain and the US have been criticized for failing to identify Mutallab as a serious security threat. He was on a US security "watch list," but wasn't prohibited from boarding a Christmas flight from Amsterdam, even though he paid for his ticket with cash and had no luggage to check, both signs that should have raised a red flag, say security experts.