ATHENS, Greece (AP) — Authorities ordered an Emirates flight to a New York City-area airport to return to Athens international airport and grounded a second airliner over security concerns Thursday, but police said nothing suspicious was found after the planes and passengers were checked.

Public ERT television said the flight recall was made following a request by U.S. authorities. Greek police officials did not confirm the source of the request when asked by The Associated Press.

Officials at Athens airport said Emirates Flight 209 to Newark Airport in New Jersey returned to Athens two hours after taking off and landed safely. The plane was escorted back through Greek airspace by two Greek air force F-16s, military officials said.

The second Emirates flight, which was scheduled to fly to Dubai, was stopped in Athens before takeoff. Police said information received about a potentially suspicious passenger was not confirmed by the inspections.