Conflicting speculations emerged on Friday concerning the party responsible for the damage caused by a mortar attack against the Hmeimim Russian air force base in Syria on December 31, 2017, with reports saying that Moscow has asked Damascus about the shelling. Russia’s Defense Ministry failed to reveal any details about what happened at the base to help identify the source and the size of the mortar used in the shooting. Russian political figures held ISIS militants trained by Washington, responsible for the attack. In the meantime, military experts from Russia were trying to avoid any seeming suspicions pointed at the Syrian regime. For its part, Syrian opposition groups said that the attack could be launched either by anti-regime groups from the Alawite sect or by Iranian-backed militias. Russia’s Kommersant newspaper was the first to write about the Hmeimim incident, reporting that seven warplanes had been destroyed in the shelling. The report pushed later the Defense Ministry to admit in a statement that the Hmeimim air base was subjected to sudden mortar shelling from a mobile group of militants. “As a result of the shelling, two servicemen were killed,” it said. Russia Today channel quoted a report published earlier by Russian-language Vestnik Mordovia newspaper concerning the type of the mortar used in the shelling. Without naming any expert, the report said that the attack against the Hmeimim air base was conducted by a Vasilek gun-mortar dating back to the 1950s and is still used by many armies of the world and produced by Russia so far. The website said that the Syrian Army does not possess this type of gun which proves that terrorists got it through Turkey and confirms that Washington is behind the attack on Hmeimim airbase. The Military Balance website confirmed that Syrian regime forces have used such kind of mortars until 2017. SMART news agency said on Friday that the Free Syrian Army received a document issued from the Syrian regime intelligence including proves that the shelling at the Hmeimim air base was launched from regime-controlled areas.