Moscow says the recent crash of a Russian Airbus A321 in Egypt’s Sinai Peninsula was possibly due to "an act of terror."
"The possibility of an act of terror is of course there as the reason for what happened," Prime Minister Dmitry Medvedev said in an interview with Rossiyskaya Gazeta newspaper, published on Monday.
Moscow has yet to formally announce its assessment of the reason for the October 31 crash of the plane, run by Russia’s Kogalymavia airline and filled with mostly Russian tourist families.
Meanwhile, Western sources suspect a bomb blast on board the plane caused the crash.
Egyptian officials, however, insist there is no evidence yet of an attack on the plane.
Russian President Vladimir Putin on Friday ordered a temporary ban on all Egypt flights.
Elsewhere, Medvedev said about 80,000 Russians were on vacation in Egypt at the time when Putin ordered the halt, as Red Sea resorts are extremely popular among Russians during winter.
He said at a government meeting Monday that "this security measure is necessary until the reason for the A321 crash is known."
Meanwhile, analysis of the black boxes of the aircraft has revealed that it was probably brought down by a bomb on board, sources close to the investigators say.
Based on the analysis of flight data and voice recorders, "everything was normal" at first; however, the conditions changed 24 minutes after takeoff and the recordings pointed to "a very sudden explosive decompression," one source said on Friday.
Another investigator told French TV station France 2 that the sound of an explosion could be heard on the black boxes, stressing that the blast was not consistent with an engine failure.
"The theory of an explosive device, with local complicity, is being taken seriously. Nothing is proven yet, but it is a real possibility," a European official said after discussing the issue with a Western intelligence agency, Reuters reported.
An affiliate of the Daesh terrorist group in Egypt has claimed to have downed the plane in retaliation for Moscow’s anti-Daesh military campaign in Syria.
"They believe that what Daesh is saying has a good chance of being credible," the European official added.