After claiming that it was behind the crash of a Russian civilian plane in Egypt's Sinai Peninsula, the Islamic State has now released a chilling video showing a plane falling from the skies and going up in flames.
Even as the Isis claim has been disputed, the group has claimed that its Sinai Province wing downed the Russian aircraft in retaliation for Russian airstrikes on Isis targets in Syria.
All 224 people on board the Russian airline Kogalymavia flight died when it crashed in a mountainous region in the north of Sinai, which has seen increasing Isis presence in recent months.
While officials had initially reported that the aircraft may have developed a technical malfunction, speculations have been rife about an Isis hand in the incident.
The new Isis video shows a chilling footage of a plane descending at a dangerous speed and then bursting into flames, and the Islamic State has called it 'proof' of their actions.
While Youtube has reportedly removed the video, some footage is still circulating online. [See VIDEO below]
"The fighters of the Islamic State were able to down a Russian plane over Sinai province that was carrying over 220 Russian crusaders. They were all killed, thanks be to God," Isis had said in a statement on Saturday.
Egyptian investigators had reportedly said that parts of the plane had caught fire while falling from the sky.
However, terror experts have lambasted the Isis claim, stating that Isis did not have weapons with enough ability or range to take down a plane flying at 31,000 feet.
Charlie Winter, a jihadism researcher, said on Twitter that the Isis claim was 'ultra vague' and that the video was 'definitely faked'.
Meanwhile, Reuters reported that Russia has grounded Airbus A321 jets flown by the Kogalymavia airline, Interfax news agency reported on Sunday, after one of its fleet crashed in Egypt's Sinai Peninsula, killing all 224 people on board.
The A321, operated by the Russian airline under the brand name Metrojet, was carrying holidaymakers from the Red Sea resort of Sharm el-Sheikh to St Petersburg when it went down soon after daybreak on Saturday.
Interfax said the Russian transport regulator Rostransnadzor had told Kogalymavia to stop flying A321 aircraft until the causes of the crash were known. However, RIA news agency cited a Kogalymavia representative as saying that the airline had not received the order from Rostransnadzor.
Egyptian and Russian investigators will begin examining within hours the contents of two "black box" recorders recovered from the airliner, which crashed into a mountainous area of central Sinai shortly after losing radar contact near cruising altitude.