Passengers at Halifax's Stanfield International Airport are facing long lineups and delays as security measures have been stepped up following an attempted Christmas Day attack on a Detroit-bound flight.

Transport Canada issued new security measures including secondary and pat-down searches for passengers on U.S.-bound flights. Travellers are also allowed only one piece of carry-on luggage, which will be searched by hand.

"Earlier this morning there were some larger than normal lineups at screening points. Those lineups weren't large enough to create any major delays, and they quickly returned to normal and things ran smoothly throughout the day," said Ashley Barnes, spokeswoman for the Halifax International Airport Authority. "But travellers should still be advised that these new security measures that have been implemented by Transport Canada are expected to cause some delays."

Passengers flying to the U.S. should arrive at the airport up to three hours before departure time, said Barnes.

An admitted al-Qaeda supporter, Nigerian Umar Farouk Abdul Mutallab, attempted to blow up Northwest Airlines Flight 253 from Nigeria via Amsterdam about 20 minutes from Detroit, U.S. security officials said. There were 278 passengers and 11 crew members aboard.

At least one passenger jumped on the man when people on the plane smelled smoke and heard what sounded like firecrackers.

The man was questioned Friday evening and was being held and treated in an Ann Arbor, Mich., hospital for burns, U.S. intelligence officers said.