A US Airways flight from Shannon, Ireland, made an emergency landing in an isolated part of Philadelphia International Airport on Wednesday afternoon after a telephone threat about a bomb on the plane.
According to AP, an investigation led to a search of the trans-Atlantic flight and passengers were questioned but nothing turned up.
Flight 777 was met by fire trucks and federal and local authorities when it landed at the airport.
Victoria Lupica, a spokeswoman for Philadelphia International Airport, told USA Today: "A threat was phoned into the airport regarding the scheduled inbound flight from Ireland.
"All bags were screened in Ireland but, out of an abundance of caution, were rescreened after the flight landed at Philadelphia."
She added: "All is clear and the bomb threat appears to be unfounded."
According to NBC Philadelphia, the 171 passengers and eight crew members were escorted off the plane and taken to a secure area to be screened and interviewed.
All inbound flights were delayed during the investigation.
Officials did not release any details about the nature of the bomb threat or where the call originated but the person who made the call could face serious criminal charges.
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