A Russian airliner carrying 224 passengers crashed into a mountainous area of Egypt's Sinai peninsula on Saturday shortly after losing radar contact near cruising altitude, killing all aboard.
A militant group affiliated to Islamic State in Egypt, Sinai Province, said in a statement it had brought down the plane "in response to Russian airstrikes that killed hundreds of Muslims on Syrian land", but Russia's Transport Minister told Interfax news agency the claim "can't be considered accurate".
The Airbus A321, operated by Russian airline Kogalymavia under the brand name Metrojet, was flying from the Red Sea resort of Sharm el-Sheikh to St Petersburg in Russia when it went down in central Sinai soon after daybreak, the aviation ministry said.
"I now see a tragic scene," an Egyptian security officer at the site told Reuters by telephone. "A lot of dead on the ground and many who died whilst strapped to their seats.
"The plane split into two, a small part on the tail end that burned and a larger part that crashed into a rockface. We have extracted at least 100 bodies and the rest are still inside," the officer, who requested anonymity, said.
Both black boxes of the plane had been found, Mohamed Hossam Kemal, the civil aviation minister, told a news conference.
Kemal said communications between the plane and air traffic control before the crash had been normal and that nothing irregular had occurred before the accident.
"The plane did not request a change of route," he said.
Egyptian Prime Minister Sherif Ismail also told the news conference that there did not appear to be any unusual activity behind the crash but the facts would not be clear until further investigations had been carried out.
Ismail said 129 bodies had so far been removed and the chances of finding survivors were now near-impossible.
Bodies were being transported to various hospitals with 34 arriving in the Zeinhom morgue in Cairo early in the evening.
Islamic State, in a statement on Twitter, said it had brought down the aircraft.
Sinai is the scene of an insurgency by militants close to Islamic State, who have killed hundreds of Egyptian soldiers and police and have also attacked Western targets in recent months. Much of the Sinai is a restricted military zone.
Militants in the area are not believed to have missiles capable of hitting a plane at 30,000 feet. Islamic State websites have in the past claimed responsibility for actions that have not been conclusively attributed to them.
Russia, an ally of Syrian President Bashar al-Assad, launched air raids against opposition groups in Syria including Islamic State on Sept. 30.
Two of Europe's largest airlines, Lufthansa and Air France-KLM, said they would avoid flying over the Sinai peninsula while awaiting an explanation on the cause of the crash.
Egyptian President Abdel Fattah al-Sisi promised Russia's President Vladimir Putin he would allow Russian experts to join the investigation.
The prime minister said a Russian team would arrive in Egypt later on Saturday night. The country is also preparing to receive the families of the victims.