CAIRO - Egyptian and international investigators on Sunday have begun probing the reasons of a Russian passenger plane that crashed in Egypt's Sinai Peninsula on Saturday, state media reported.

The Egyptian and the Russian investigators have started analyzing the plane's two black boxes data recorders which have been recovered late Saturday.

Two investigators specialized in the safety of the planes from the French Agency for Safety of Civil Aviation, six consultants from Airbus and two Germans in the same field will join the Egyptian-Russian team later on Sunday, state-run Ahram website reported.

Emergencies Minister of Russia Vladimir Puchkov arrived in Cairo on Saturday with a team of experts to help with the Egyptian-led investigation.

Rescuers had found 163 bodies of 224 passengers and crew, the cabinet statement said on Sunday, adding the search has widened.

A Russian airliner crashed into a mountainous area in the restive Sinai on Saturday. A militant group affiliated to Islamic State (IS) in Egypt claimed responsibility for the crash.

Egyptian Prime Minister Sherif Ismail said on Saturday it was impossible to determine the cause of the crash until the black box was examined.

"Experts asserted that a plane flying that high technically cannot be shot down," Ismail said, adding that no "irregular" activities were believed to be behind it.