"As we helped the brotherly Syrian people, we tested over 200 new types of weapons," said Vladimir Shamanov, a former commander of Russia's airborne troops who now serves as head of the Russian Duma's defence committee.

"It's not an accident that today they are coming to us from many directions to purchase our weapons, including countries that are not our allies," he said.

"Today our military-industrial complex made our army look in a way we can be proud of," he said.

Russia, a close ally of the Syrian government in the protracted multi-front war, has been accused of indiscriminate bombing throughout the conflict causing massive casualties.

The latest criticism focuses on the air strikes against the enclave of Eastern Ghouta, where more than 350 civilians have been killed in five days, but the Kremlin denied involvement in the regime-led assault.

Shamanov's remarks also come amid reports that Russia has deployed its Su-57 stealth fighter prototype in Syria, where two such planes were reportedly spotted Wednesday.

Photos of the fifth generation jet, allegedly over Syria, were re-posted by various state media Thursday.

A source in the defence ministry confirmed to RBK news agency that the two planes were sent to the Hmeimim base "for a test in real conditions."

Kremlin spokesman Dmitry Peskov declined to comment on the reported deployment of Su-57.