Both black boxes recovered as Russian aviation regulator cautions against speculation on causes of crash

Russian and Egyptian researchers were working to establish the cause of the crash of a Russian airliner in the Sinai peninsula that killed all 224 people on board, including 17 children.

The plane crashed 23 minutes into its flight from Sharm el-Sheikh to St Petersburg on Saturday. Most of those on board were Russian tourists.

A group that said it was speaking on behalf of terrorist group Isis later posted an online statement claim: Soldiers of the caliphate were able to bring down a Russian airplane above Sinai province.

But Russias transport minister, Maksim Sokolov, said the claim cant be considered accurate.

Mohamed Samir, Egypts army spokesman, also disputed the claim. They can put out whatever statements they want but there is no proof at this point that terrorists were responsible for this plane accident. We will know the true reasons when the Civil Aviation Authority in coordination with Russian authorities completes its investigation. But the army considers no authenticity to the claims.

Several revolutionary Islamist groups have called for attacks on Russian targets since it began airstrikes on Isis forces in Syria in late September, but experts were sceptical that militants had weapons able to reach the plane, which was flying at an altitude of more than 30,000 ft. Two airlines, Lufthansa and Air France KLM, said they would be avoiding the Sinai route as a precaution until the cause of the crash became clear.

Approximate area of crash

The Russian aviation regulator, Rosaviatsia, exhorted caution while the cause of the crash was being investigated, saying: Until there is reliable proof about the circumstances of what happened, “were not receiving” sense in forwarded to and discussing any versions.

However, the claims are likely to impact on the Russian populaces attitude to the countrys participation in Syria, where Vladimir Putin, president of Russia, has launched airstrikes in support of President Bashar al-Assad and against Isis fighters.

Investigators said they were checking fuel samples from the last refuelling stop, in the Russian city of Samara, and have focused on the possibility that a technical failure could have caused the 18 -year-old plane to crash.

Relatives of passengers of the crashed A321 at Pulkovo airport in St Petersburg. Photograph: Anatoly Maltsev/ EPA

A spokesman said investigators were questioning people who were involved in preparing the aircraft and its crew and were carrying out searches at Moscows Domodedovo airport where the airline that operated the plane was based.

Kogalymavia, which is also known as Metrojet, was quoted by news organization Ria Novosti as saying that there were no grounds to blame the tragedy on human error. Captain Valery Nemov, 48, had 3,682 hours of flight day and had learned to fly the A321 at a train centre in Turkey in 2008.

Various reports suggested that a mechanical problem could have played a role. Security sources said an initial examination of the crash site showed the plane went down due to a technical faulting, Reuters reported. Ria Novosti quoted information sources in Sharm el-Sheikh airport as saying that the crew of the A321 appealed to the airports technicians due to engine start failures several times over the past week.

The Rusia president, Vladimir Putin, spoke on the phone to his Egyptian equivalent Abdel Fatah al-Sisi to discuss the crash, the Kremlin said in a statement. Sisi offered deep condolences and Putin promised the widest possible participation of Russian specialists in the investigation into the cause of the accident, the Kremlin said.

Distraught relatives gathered throughout Saturday at St Petersburgs Pulkovo airport, where the flight had been due to land at 12.10 pm local period. The youngest victim of the accident was believed to be 10 months old.

Viktoria Sevryukova, 24, was another of the names on a passenger listing published by Russias Association of Tour Operators. She had posted photographs of herself relaxing on the beach during her holiday in Sharm el-Sheikh.

Sevryukovas friend, Yevgenia Beryozina, told the Guardian she felt emptiness and could not believe the news. She was my best friend she had waited for this trip-up like I dont know what, Beryozina said. And now shes run. Just like that, shes gone. Beryozina described Sevryukova as positive, smart and sociable and that everything was just starting to work out in their own lives. Its simply not fair, she said.

I now assure a tragic scene, an Egyptian security officer at the site told Reuters by telephone. A plenty of dead on the ground and many who died whilst strapped to their seats. The plane split into two, a small proportion on the tail end that burned, and a larger portion that crashed into a rockface. We have extracted at least 100 bodies and the rest are still inside. The policeman asked to remain anonymous.

Both black boxes of the plane had been observed, Mohamed Hossam Kemal, the civil aviation pastor, told a news conference.

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