A plane flying from Paris to Cairo has crashed into the Mediterranean Sea en route on Thursday morning.
Egypt's Aviation Ministry said 30 Egyptians, 15 French, one Briton and a Belgian were among the 66 people on board the EgyptAir flight.
The plane was carrying 56 passengers and 10 crew. There were three security personnel onboard.
Airbus has confirmed that missing flight MS804 has crashed into the Mediterranean Sea.
The manufacturer said the A320 operated by EgyptAir "was lost" at around 2.30am local time during its scheduled flight from Paris to Cairo, the UK Independent reported.
"An official source at EgyptAir stated that Flight MS804, which departed Paris at 23:09 (CEST), heading to Cairo has disappeared from radar," the airline said on its official Twitter account.
EgyptAir said the plane was traveling at an altitude of 37,000 feet (11,280 meters), and disappeared in Egyptian air space at 02:30 a.m., some 280 kms (165 miles) from the Egyptian coastline, before it was due to land at 03:15 a.m.
Some international media had reported security experts stating the plane was attacked by terrorists.
In a statement on the EgyptAir website, the airline said it "denies all misleading information published by news websites and on the social media channels regarding the reasons of the disappearance" of the flight.
It said the cause of disappearance hasn't been yet confirmed.
"There was nothing unusual," EgyptAir vice chairman Ahmed Adel told Reuters. "The search and rescue aircraft from the Egyptian air force are at the position where we lost contact. They are still looking and so far there is nothing found."
Egyptian state newspaper Ahram reported no distress call was made and the last contact was 10 minutes before the plane disappeared.
A Greek defense ministry source said authorities were also investigating an account from the captain of a merchant ship who reported a 'flame in the sky' some 130 nautical miles south of the island of Karpathos.
The weather was clear at the time the plane disappeared, according to weather reports.
An Airbus A321 operated by Russia's Metrojet crashed in the Sinai on Oct. 31, 2015, killing all 224 people on board. Russia and Western governments have said the plane was likely brought down by a bomb, and the Islamic State militant group said it had smuggled an explosive device on board.
While in March, an EgyptAir plane flying from Alexandria to Cairo was hijacked and forced to land in Cyprus by a man who was wearing what authorities said was a fake suicide belt. He was arrested after giving himself up.