Plane from Ireland lands in Philadelphia after reported threat (VIDEO)

A plane from Ireland underwent a rigorous security check in Philadelphia after someone called in a threat on Wednesday, local police told NBC News.

The Associated Press reported FBI agents at the scene, but federal agents and police officials later told NBC the threat could not be substantiated. 

CBS News, citing an unnamed federal government official, said the threatening call concerned a potential bomb threat. 

"An FBI agent got on the plane and told us that someone made a bomb threat or something like that," passenger Molly Cross told NBC. 

It did not appear that the Boeing 757 in question — US Air flight 777 from Shannon, Ireland to Pittsburgh — actually made an emergency landing in Philadelphia.  

Flights into the airport were temporarily put on hold, said NBC News. 

Homeland Security's Joint Terrorism Task Force is said to be assisting the police.  

All 171 passengers aboard the flight were taken safely from the plane to the terminal by bus; they had their luggage searched out of caution, according to FOX News. The aircraft was isolated and screened.