US President Barack Obama has ordered a review of air security measures after a botched terror attack and demanded to know how a Nigerian youth with explosives managed to sneak into a transatlantic American jet. White House press secretary Robert Gibbs said in Washington that Obama wanted to know how a man carrying explosives had managed to board the Northwest Airlines flight from Amsterdam to Detroit on Christmas day without being detected. He said, the president wants to review some of these procedures and see if they need to be updated. 23-year-old Nigerian, Umar Farouk Abdulmutallab, claiming to have links with al Qaeda was on a US security watch list after his father alerted authorities about his behaviour. Gibbs said Obama is receiving regular briefings by his national security staff on the incident. He said, Abdulmutallab, was on a broad watch list of 550,000 names since November.He added that the list does not automatically bring tighter screening of individuals and the President has ordered a review of the procedures for determining which people on the list undergo more stringent checking.