CAIRO – An EgyptAir flight from Paris to Cairo has disappeared from radar with 66 people on board, the airline says.
The Airbus A320 went missing over the eastern Mediterranean, soon after entering Egyptian airspace.
The Egyptian military has denied a report from EgyptAir that a distress signal was sent by the plane.
There were 56 passengers – including three children – seven crew members and three security personnel on board Flight MS804, the airline said.
The airline said the passengers included 30 Egyptians, 15 French citizens, one Briton, two Iraqis, as well as people from Canada, Belgium, Kuwait, Saudi Arabia, Algeria, Sudan, Chad and Portugal.
Flight MS804 left Paris' Charles de Gaulle airport at 23:09 local time on Wednesday (21:09 GMT) and was scheduled to arrive in the Egyptian capital soon after 03:15 local time on Thursday.
It was flying at 37,000ft (11,300m) over the eastern Mediterranean when contact was lost, at 02:30 Cairo time (00:30 GMT).
In what is thought to have been the last known contact with the plane, Greek air traffic controllers spoke to the pilot over the island of Kea, just south-east of Athens, and he "did not mention any problems", Kostas Litzerakis of Greece's civil aviation department told Reuters news agency.
A Greek aviation official told the AFP news agency that the plane crashed "around 130 nautical miles" off the southern Greek island of Karpathos, although this has not been confirmed.
Both the Greek and Egyptian armed forces are involved in the search for the plane. France says it is sending boats and planes to help in the operation.
There was some confusion over whether a distress signal was sent by the plane.
Egypt's state-run newspaper al-Ahram quoted an EgyptAir statement as saying the Egyptian army's rescue and search had received a distress call from the plane at 04:26 local time – which would be around two hours after the flight disappeared.
But the Egypt's military subsequently said that no such signal was received.
Airbus, in a statement on its Facebook page, confirmed "the loss" of the 13-year-old plane, saying "our concerns go to all those affected".