Reports of fireball amid search for missing EgyptAir flight
Greek authorities said they found pieces of wreckage from the plane in Egyptian territorial waters, near the Greek islands of Crete and Karpathos respectively.
Speaking at a press conference in Paris, French President Francoise Holland said the plane went down at sea.
He added that he planned to co-operate closely with his Greek and Egyptian counterparts, saying that "no hypothesis is being ruled out and none is being favoured" on the cause of the crash.
The Greek defense minister, Panos Kammenos, said the plane swerved suddenly just after it entered Egyptian airspace and plunged into the Mediterranean.
EgyptAir tweeted that the Airbus A320-232 was at an altitude of 37,000 feet when contact was lost about 16km inside of Egyptian airspace while it was over the Mediterranean Sea about 450km from the coast.
It had departed Charles Du Gaulle airport in Paris, France at 23:09 GMT (11.09AM NZT) and it was expected to land in Cairo about 3:15am Cairo time.
The Egyptian Army is now denying receiving a distress call from a missing A320, telling Egyptian media that earlier EgyptAir reports were wrong.
Greek authorities are investigating claims that residents of a Greek island saw a ball of fire, or flame in the sky around the time the flight lost contact with radar.
Egyptian Prime Minister Sherif Ismail has arrived at the crisis centre at Cairo Airport, and is said to be issuing guidance to concerned authorities.
He said it was too early to say whether a technical problem or a terror attack caused the plane to crash. "We cannot rule anything out," he told reporters at Cairo airport.
The nationalities of the passengers on board the aircraft were revealed by the airline this evening, and are: 15 French, 30 Egyptian, one Briton, one Belgian, two Iraqis, one Kuwaiti, one Saudi, one Sudanese, one Chadian, one Portuguese and one Algerian.
Among those on board were a child and two infants, the airline said, and the 10 crew members included 3 security staff.
The aircraft was built in 2003 and the airline tweeted that it was worth mentioning that the aircraft's pilot had logged 6275 flight hours, including 2101 hours flying the same model of plane, while the co-pilot had logged 2766 hours.
"Egypt air is following the situation closely with the competent authorities through the integrated operations centre," it tweeted in Arabic.
Search and rescue teams, including Egyptian armed forces, are currently searching for the aircraft, and include teams from both Egypt and Greece.
A number of private vessels had also been enlisted to search for the aircraft in the Mediterranean Sea.
EgyptAir tweeted that was trying to arrange to fly passenger's families closer to the airport, and said it had been providing doctors, translators and all necessary services to the families.
The airline has set up a phone number for relatives of those on board looking for information - +202 259 89320 outside Egypt or from mobiles in Egypt, or 0800 7777 0000 from any landline within Egypt.
An EgyptAir plane was hijacked and diverted to Cyprus in March. A man who admitted to the hijacking and is described by Cypriot authorities as "psychologically unstable" is in custody in Cyprus.
The incident renewed security concerns months after a Russian passenger plane was blown out of the sky over the Sinai Peninsula.
The Russian plane crashed in Sinai on October 31, killing all 224 people on board.
Moscow said it was brought down by an explosive device, and a local branch of the extremist Islamic State group has claimed responsibility for planting it.
In 1999, EgyptAir Flight 1990 crashed into the Atlantic Ocean near the Massachusetts island of Nantucket, killing all 217 people aboard.
US investigators filed a final report that concluded its co-pilot switched off the autopilot and pointed the Boeing 767 downward, but Egyptian officials rejected the notion of suicide altogether, insisting some mechanical reason caused the crash.
