Multiple Russian Aircraft destroyed in Syria by rebel shelling

In the single biggest loss of military hardware for Russia since it launched air strike in Syria in autumn 2015, more than 10 servicemen were wounded in the attack by "radical Islamists," the report said.

At least four Su-24 bombers, two Su-35S fighters and an An-72 transport plane, as well as an ammunition depot, were destroyed by the shelling, Kommersant said on its website, citing two "military-diplomatic" sources.

Kommersant said the Russian defense ministry had not commented. Reuters was not able to immediately reach the ministry.

Earlier on Wednesday, the ministry said a Mi-24 helicopter had crash-landed in Syria on Dec. 31 due to a technical fault and two pilots died.

Last month, Russia began establishing a permanent presence at Hmeymim and a naval base at Tartous although President Vladimir Putin has ordered a "significant" withdrawal of his military from Syria, declaring their work largely done.