A massive search was under way for an EgyptAir plane that disappeared over the Mediterranean with 66 people on board, with suspicions swiftly focusing on a terrorist motive.

A massive search was under way for an EgyptAir plane that disappeared over the Mediterranean with 66 people on board, with suspicions swiftly focusing on a terrorist motive.

Egypt's aviation minister said that while it was too soon to say why the Airbus A320 flying from Paris to Cairo had vanished from radar screens, a "terrorist" attack would be a more likely scenario than a technical failure.

The tragedy raised fears of a repeat of the bombing of a Russian passenger jet by the ISIL Takfiri group over Egypt last October that killed all 224 people on board.

The plane disappeared between the Greek islands and the Egyptian coast in the early hours of Thursday morning, without its crew sending a distress signal.

Greek Defense Minister Panos Kammenos said the aircraft had swerved sharply twice in Egyptian airspace before plunging 22,000 feet (6,700 meters) and disappearing from radar screens.

Both Egypt and Greece dispatched aircraft and naval vessels on a major search mission. They were expected to be joined by French teams, while the US sent a surveillance plane to help with the operation.

Egypt's President Abdel Fattah al-Sisi demanded an "intensified search" for the aircraft after reports that wreckage from the plane had been found were retracted.

EgyptAir initially said on its Twitter account that the Egyptian authorities had recovered wreckage from the missing aircraft but the head of the Greek air safety authority told AFP that debris found close to the area where the jet went down did "not come from a plane".

French President Francois Hollande said the plane had "crashed", as authorities in both Paris and Cairo opened investigations.

Egypt's Aviation Minister Sherif Fathy said he was unable to "deny the hypothesis of a terrorist attack or something technical".

The airline said 15 French citizens were among the 26 foreign passengers on the plane, who also included a Briton and at least one Canadian.

Both France and Egypt have come under attack by ISIL Takfiris in the past year, and Hollande promised a comprehensive probe into the cause of the crash.