Footage has emerged online, purporting to be evidence Islamic State shot down an airliner that crashed in Egypt's Sinai Peninsula on Saturday.
The grainy clip shows an unidentifiable plane flying at height before exploding and plummeting downwards.
The footage can not be verified and Egyptian officials have already said the crash was due to a technical fault, dismissing the claims.
On Saturday IS released a statement that said: "Soldiers of the Caliphate were able to bring down a Russian plane above Sinai Province with at least 220 Russian crusaders aboard.
"They were all killed, praise be to God. O Russians, you and your allies take note that you are not safe in Muslims lands or their skies.
"The killing of dozens daily in Syria with bombs from your planes will bring woe to you. Just as you are killing others, you too will be killed, God willing."
Although they didn't say how they would have downed the plane, experts say the man-portable MANPADs the group could have would not be able to shoot a plane down at that height.
Two experts said it was possible IS planted a bomb on the plane but both remained sceptical and said it could prove a false claim, which IS has made before.
The The Airbus A-321 was bound for St Petersburg crashed shortly after taking off from the resort of Sharm el-Sheikh.
It was carrying 221 Russians and three Ukrainians, mainly tourists returning from their holidays.
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Sinai Plane Crash
There were 17 children on board.
Flight 7K9268 vanished from radars just 23 minutes after take-off.
Although the so-called Islamic State terror group tried to claim responsibility for the crash, many were sceptical, with one expert calling it "almost certainly nonsense".
The aircraft belonged to Russian airline Kogalymavia, also known as Metrojet, and was carrying mainly Russian tourists at the time.
According to FlightRadar24, the plane was descending steeply in its final minutes.
An Egyptian official said the pilot had reported a technical problem and was trying to land at the nearest airport.
The wife of the co-pilot claims her husband had complained about the state of the plane prior to the flight.
She said: "He complained before the flight that the technical condition of the aircraft left much to be desired,"