A still image taken from a video footage and released by Russia's Defence Ministry on September 5, 2017, shows the Russian frigate Admiral Essen in the Mediterranean Sea firing a Kalibr cruise missile at Islamic State targets near the Syrian city of Deir al-Zor. (REUTERS PHOTO)

MOSCOW, Sept. 14 (Xinhua) -- Two Russian submarines fired seven Kalibr sea-based cruise missiles at crucial facilities of the Islamic State (IS) in Syria from underwater position in the eastern Mediterranean, the Russian Defense Ministry said Thursday.

The diesel-electric attack submarines Veliky Novgorod and Kolpino struck control points, communication centers, and weapons and ammunition depots in IS-controlled areas southeast of the city of Deir ez-Zor located in northeastern Syria from a distance of 500-670 km, the ministry said in a statement.

All targeted objects were hit, the ministry said.

Syrian government troops supported by Russian air and naval strikes are successfully advancing in various parts of the war-torn country, having liberated most of it from the IS and other terrorist groups.