Egypt said the plane carried 56 passengers including "15 French, 30 Egyptians, one British, one Belgian, two Iraqis, one Kuwaiti, one Saudi, one Sudanese, one Chadian, one Portuguese, one Algerian and one Canadian," besides three security personnel and seven crew members -- 66 people in total. Among the passengers there were also one child and two infants.
EgyptAir said the pilot of the plane had 6,275 hours of flying experience, including 2,101 hours on the same model, while the co-pilot had 2,766 flying hours.
Manufactured in 2003, the plane left Paris at 11:09 p.m. local time (2109 GMT) on Wednesday for a three-hour-and-45-minute journey.
EgyptAir also said concerned authorities and an inspection team which involves Egyptian and Greek military jets, have launched a search operation. The airline is following the situation through an integrated operation center.
French President Francois Hollande and his Egyptian counterpart, Abdel-Fattah al-Sisi, also vowed on Thursday to "work closely to establish as soon as possible the circumstances of the disappearance" of EgyptAir flight MS804, the Elysee said in a press release.
Foreign ministries of France and Egypt have agreed to "the need for a close coordination between the two countries in the assistance to the families of the passengers, as well as in the investigation for the cause of the disappearance," according to the press release.
Speaking to local radio, French Prime Minister Manuel Valls said the French government is "in close contact with the Egyptian military and civil authorities."
"France is ready to participate in the searches," he said.
A toll-free number has been announced for friends and families of the passengers on board.