By Mark Abrams

PHILADELPHIA (CBS) — There were some tense moments at Philadelphia International Airport on Tuesday afternoon after the pilot of a commuter plane coming in for a landing reported he thought a flare or some other device had been fired at his aircraft.

Authorities say Piedmont Flight 4321 from Elmira, New York to Philadelphia, was on final approach with 39 passengers and three crew members aboard.

The pilot was preparing to land on runway 17, when he reported a problem to air traffic controllers.

“There’s a flare back there – 500 feet, Piedmont 4321 on final,” the pilot can be heard saying.

“There’s a what? I missed it, sorry.”

“It looked like a flare that was shot up,” the pilot says.

A co-pilot also reported that it looked like something exploded about 50 feet from the right wing.

The plane landed safely, as did a second commuter aircraft heading for the runway.

But Philadelphia police and federal officials responding to the first reports declared runway 17 closed. It reopened about a half hour later.

Philadelphia police confirmed they received a 9-1-1 call about 2 p.m. about a flare being shot from an intersection near the airport, but responding officers found nothing.

A federal law enforcement official says the incident is not considered a terrorist act.

The runway reopened at 2:15 p.m. and the incident remains under investigation by Philadelphia police, the F.B.I. and the FAA.

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