A passenger attempted to light an explosive device but was subdued by a federal air marshal aboard an airliner flying from Washington to Denver on Wednesday night, said an NBC News report.

 

United Flight 663, a Boeing 757 with 157 passengers and six crew members aboard, landed safely at Denver International Airport, airline and airport officials said.

 

Sources told NBC News that the passenger who was subdued was a Qatari diplomat.

 

The report says that questions have been raised about why Umar Farouk Abdulmutallab, who was charged with trying to blow up the airliner, was not stopped before he got on the flight.