UFO?
© Todd Plitt/USA TODAY
Was that a drone flying over metro New York Monday?

That's what a pilot for Italian carrier Alitalia reported seeing from the cockpit of a flight landing at New York's JFK Airport. The pilot informed the air traffic control tower, and now his spotting has drawn the attention of both Federal Aviation Administration and counter-terrorism officials.

"The FAA is investigating a report... he saw a small, unmanned or remote-controlled aircraft while on final approach to Runway 31 Right," FAA spokeswoman Laura Brown says in a statement quoted by CNN. "The sighting was approximately four to five miles (from) the airport at an altitude of approximately 1,500 feet."

New York's Joint Terror Task Force also is investigating, according to both ABC News and the New York Post report. Both cite unnamed sources.

"He was very clear as to what he saw," a source tells the Post about the pilot's account of "a black drone."

Other than the pilot's sighting, the Alitalia flight landed at JFK without incident.

An aviation expert tells the Post it's possible the unverified flying object was an enthusiast's model aircraft. However, the expert - also unnamed - said he couldn't recall any other incidents in which such a model veered so close to a commercial aircraft.

Even if it was a remote-controlled recreational model, FAA guidelines say such objects may only fly to 400 feet high and must alert air traffic control if they are going to fly within three miles of an airport, according to CNN.

The object reported by the Alitalia pilot was at about 1,500 feet, ABC News' sources say.

CNN adds that "flying unmanned aerial vehicles is illegal for most business purposes; however, governments and public entities such as police departments can apply for permission to operate them."