EgyptAir flight MS804 from Paris to Cairo disappeared from radar early Thursday morning. Egyptian officials believe that the a mid-air explosion cause the plane to crash into the Mediterranean. Egypt’s Sherif Ismail said that all possible causes of the explosion were being examined – including terrorism.

Airline officials initially said the plane emitted no distress signal prior to it disappearing from radar, but later stated that in fact the plane’s emergency beacon had been detected some two hours after the last radar contact. 

The crew of a ship not far from the plane’s last known location claimed to have seen a huge fireball in the sky.

The Airbus A320 plane took off from the Charles de Gaulle Airport in Paris at 11:09 p.m. (CEST) last night, carrying 56 passengers and 10 crew members.

In the middle of the flight, radio contact with the plane was lost, and the flight disappeared from radar.

While there has been no formal confirmation that flight MS804 did indeed crash, an Egyptian aviation official told AP that mounting evidence tended to support that conclusion.

“The possibility that the plane crashed has been confirmed,” said the official.

A search has now begun for debris from the crashed plane off the Greek island of Karpathos.

French security officials said they were not ruling out terrorism as a possible cause of the crash.

Last October an Airbus A321 jetliner operated by the Russian Metrojet company crashed in the Sinai Peninsula, likely the result of a bomb smuggled onboard by ISIS terrorists. An EgyptAir mechanic with ties to ISIS is suspected of sneaking the bomb onto the Metrojet plane.