A Russian airliner carrying 224 passengers and crew crashed in Egypt's Sinai peninsula on Saturday, the Egyptian prime minister's office and civil aviation ministry said.
The Airbus A-321, operated by Russian airline Kogalymavia with registration number KGL-9268, was flying from the Sinai coastal resort of Sharm el-Sheikh to St Petersburg in Russia when it went down in a desolate mountainous area of central Sinai soon after daybreak.
The plane was carrying 217 passengers, 17 of them children, and seven crew. Most of them were Russian tourists. Egyptian officials said that all on board had died.
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".
Islamic State, in a statement on Twitter, said it had brought down the aircraft. "You who kill will be killed."
Russia, an ally of Syrian President Bashar al-Assad, launched air raids against opposition groups in Syria including Islamic State on September 30.
Security sources said they had no indication the Airbus had been shot down or blown up. But in an illustration of sensitivity of the crash, Egypt invited Russian authorities to take part in the investigation.
Islamist fighters in Sinai 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.
Sergei Isvolsky, a spokesman for Russian aviation authority Rosaviatia, told Interfax news agency that the plane took off from Sharm el-Sheikh at 03.51 GMT and ground contact with it was lost about 25 minutes later.
According to Egyptian media at least 40 ambulances have been sent to the scene.
The security officer at the scene told Reuters by telephone that search and rescue teams heard voices in a section of the plane.
"I now see a tragic scene. A lot of dead on the ground and many who died while strapped to their seats," the officer said.
"The plane split into two, a small part on the tail end that burned and a larger part that crashed into a rock."
The security officer said 120 intact bodies had been found.
"We are hearing a lot of telephones ringing, most likely belonging to the victims, and security forces are collecting them and putting them into a bag," he said.
Rosaviatsiya said in a statement that the flight had been due into St Petersburg's Pulkovo airport. It failed to make scheduled contact with Cyprus air traffic control 23 minutes after take-off and disappeared from the radar.
Egypt's civilian aviation ministry said the plane had been at an altitude of 31,000ft when it disappeared. Initial reports indicate that it may have suffered a technical failure. The Russian RIA news agency, citing sources at Sharm el-Sheikh, said: "The pilot contacted the dispatcher and reported technical problems, asking for a change of the route and a landing at Cairo airport, after which communication was broken."
Live flight tracking service Flight Radar 24's Mikail Robertson told the BBC that the plane had started to drop very fast, losing 1,500m in one minute before coverage was lost.
A middle-aged man in a grey overcoat, who gave his first name as Nayeel, wept as he spoke to reporters as he came out of a hotel near St Petersburg's Pulkovo airport, where a special reception centre has been set up for families of the victims.
He said that his wife had been on the plane.
"At six am she sent me a text message saying: I'm boarding. God be with me.' And that was it," he said. The man said the rest of the family had already returned from a holiday in Egypt, but his wife had opted to stay on, which is why she was on the Saturday morning flight.
Additional reporting by Reuters.
