'They want to take credit for it': Experts are skeptical of ISIS' claims it downed a Russian aircraft
But experts and authorities have pushed back on that claim, questioning whether the group would even have the ability to carry out such an operation.
A statement issued on what appears to be the ISIS-affiliated group's website said the plane carrying 224 passengers was taken down in retaliation for Russia's airstrikes in Sham - the Arabic term for the region bordering the eastern Mediterranean, also known as the Levant.
"This is to show the Russians and whoever allies with them that they shall have no safety in Muslim lands or airspace," the statement read.
On Sunday, investigators determined that Kogalymavia Flight 9268 - an Airbus 321 that lost contact with air traffic control 23 minutes after taking off from Sharm el-Sheikh in the Sinai peninsula - broke up in mid-air at a high altitude.
Still, experts have regarded the group's claims of responsibility with clear skepticism. The fact that the Airbus broke up in mid-air does not necessarily indicate that it was bombed or struck by a surface-to-air missile, and it is doubtful that a man-portable air-defense systems (MANPADS) would even be able to strike a plane cruising at such a high altitude.
"Whether or not ISIS took down the Russian plane, they want to take credit for it," geopolitical expert Ian Bremmer, the president of Eurasia Group, tweeted on Saturday.
"Putin's Syria intervention makes Russia a top target."
Mokhtar Awad, an analyst with the Center for American Progress, echoed this sentiment, telling the Guardian on Saturday that Wilayat Sinai "has been under some pressure" over the past few months and may have been eager to take credit for such a major incident.
Moreover, he noted, "Even the most sophisticated surface-to-air missiles cannot reach that high an altitude and are only a threat during periods of take-off or landing, but the plane had already climbed to its target altitude (from what we know thus far) when it began to likely experience technical failures."
Jean-Paul Troadec, former director of France's BEA aviation investigation agency, noted that the claim "seems unlikely."
"You would need hard-to-use missiles" to shoot down a plane at that altitude. "So it seems unlikely," Troadec told AFP on Saturday.
"This requires trained people and equipment that IS does not have, to my knowledge."
But as many experts have pointed out, any missiles ISIS is known to have are not sophisticated enough to reach aircraft flying at 31,000 feet, as the Airbus was at the time it lost contact with air traffic control.
"The most advanced anti-air weapon #ISIS has is SA-18 Igla MANPADS, which can reach 10,000ft - way below altitude of #Russia airliner," Charles Lister, a Middle East expert and visiting fellow at the Brookings Doha Center, tweeted on Saturday.
Regarding ISIS' claim, Lister said there were three possibilities: First, that it is false; second, that there was a bomb already on the plane; or third, that ISIS somehow has advanced air-defense missiles.
"Option (3) is least likely (#Egypt not known to have lost AD/SAM systems)," Lister tweeted.
"Option (2) is feasible, but #ISIS has history of (1) - Bardo Museum," he said, referring to ISIS' claim that it was responsible for the attack on Tunisia's Bardo Museum in March, a declaration that was later debunked.
Regardless, three major airlines -Emirates, Air Arabia, and flydubai - have since decided to re-route flights that were scheduled to fly over the scene of the crash.