A Russian passenger plane with more than 200 people aboard crashed in Egypt's Sinai Peninsula on Saturday, according to the Egyptian Prime Minister's office.
A Russian Airbus A-321 aircraft carrying a total of 224 people crashed in central Sinai, the prime minister's office said in a statement.
According to Egypt's Civil Aviation Authority, the plane lost contact with air-traffic controllers shortly after taking off from the Egyptian Red Sea resort city of Sharm el-Sheikh en route to St Petersburg.
Russia's aviation authority, Rosaviatsiya, said the passenger plane – operated by Russian air carrier Kogalymavia – had taken off at 03:51 GMT and had been due to arrive at St. Petersburg's Pulkovo Airport at 12:10 GMT.
Rosaviatsiya said the plane had failed to make scheduled contact with Cypriot air-traffic controllers before disappearing from radar.
A source at the Russian embassy in Cairo said that all passengers on board the ill-fated plane were Russians.
The Egyptian authorities, meanwhile, said a cabinet-level crisis committee had been established to look into the causes of the crash.
According to local media, rescue workers have reached the crash site near the North Sinai city of Arish.
An Egyptian security source said the crash had left "no survivors".
Egyptian authorities, however, have yet to officially confirm the assertion.
An Egyptian military officer said that 100 bodies, including those of 15 children, had been extracted from the wreckage, according to television channel Russia Today.
An Egyptian security source, meanwhile, ruled out the possibility that the incident had been caused by militant activity, attributing Saturday's deadly crash to a technical malfunction.
North Sinai has been the epicenter of a violent insurgency – which has mainly targeted Egyptian security personnel – since the ouster in mid-2013 of democratically elected President Mohamed Morsi by the army.