Security tightened for U.S.-bound air passengers

Passengers wait to check in their luggage at Detroit Metropolitan airport in Romulus, Michigan December 26, 2009.

WASHINGTON (Reuters) - Airline passengers headed for the United States faced tighter security measures on Saturday after an attempt to blow up a U.S. jet bound for Detroit, including pat-downs and an order to stay seated during the last hour of flight, airlines and security officials said.

Air Canada advised U.S.-bound travelers to arrive early at airports to allow extra time for security screenings, including additional personal searches.

"Passengers should also expect flight delays, cancellations and missed connections, and limit themselves to a single piece of carry-on baggage," Canada's largest airline said on its website.

"New rules imposed by the U.S. Transportation Security Administration also limit on-board activities by customers and crew in U.S. airspace that may adversely impact on-board service," Air Canada said.

"Among other things, during the final hour of flight customers must remain seated, will not be allowed to access carry-on baggage, or have personal belongings or other items on their laps."

Singapore's Sunday Times reported that the city state's Changi Airport, a major regional transit center, had also increased security measures for non-stop U.S.-bound flights, including pat-down searches.

"One hour before the plane lands in a U.S. airport, all passengers must be seated, and should not have any baggage near them or covered with any blanket. The in-flight entertainment system would also be turned off," the Sunday Times quoted a Singapore Airlines spokesman as saying.

U.S. authorities on Saturday charged a Nigerian man with trying to blow up a Delta Airlines passenger plane with high explosives and were investigating his claim that he had links to al Qaeda.

The suspect, who was being treated for burns at a Michigan hospital, was overpowered by passengers and crew on the Delta Air Lines plane from Amsterdam on Christmas Day.

The TSA website said only that: "Passengers flying from international locations to U.S. destinations may notice additional security measures in place. These measures are designed to be unpredictable, so passengers should not expect to see the same thing everywhere. Due to the busy holiday travel season, both domestic and international travelers should allot extra time for check-in."

(Writing by Eric Walsh; Editing by Chris Wilson)