A US Airways flight from Ireland's Shannon Airport has landed safely at Philadelphia International Airport after an unspecified threat, police and the airline have said.

"There was some type of threat made, but nothing specified," a spokeswoman for the Philadelphia Police Department said on Wednesday.

Rather than following the usual landing procedure, the passengers were isolated and screened, and the luggage was screened, police said.

Flight 777 landed safely and without incident at its intended destination around 18:00 GMT, airline spokesman Andrew Christie said.

"We were aware of a possible security issue with the flight and out of an abundance of caution taxied the aircraft to a remote location, where it was met by law enforcement and emergency personnel," Christie said.

All 171 passengers and eight crew members exited the plane by the stairs and were taken to the terminal by bus, Christie said.

WPVI Television, a local news channel, reported on Wednesday that the plane received a bomb threat and said at least three airport buses had parked next to the plane.

Source: Agencies