“An informed source at EGYPTAIR stated that Flight no. MS804 which departed Paris at 23:09 (CEST) heading to Cairo has disappeared from radar,” it said on Thursday.
The Airbus A320 was flying at 37,000 feet (11,300 miles) when it went missing over the eastern Mediterranean, 10 miles into the Egyptian airspace.
An official said the plane lost contact with radar at 02:45 Cairo time (00:45 GMT).
Another tweet said EgyptAir "has contacted the concerned authorities and bodies and inspection is underway through the rescue teams."
An Airbus A321 operated by Russia's Metrojet crashed in Egypt's Sinai peninsula on October 31, 2015, killing all 224 people on board.
The plane was likely brought down by a bomb, and the Daesh Takfiri group said it had smuggled an explosive on board.
In March, an EgyptAir plane flying from Alexandria to Cairo was hijacked and forced to land in Cyprus by an "unstable" man who demanded to see his ex-wife; Press TV reported.
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