Moscow fired 18 missiles from ships in its Caspian Sea fleet at seven targets in the Raqa, Idlib and Aleppo provinces, defence minister Sergei Shoigu was quoted as saying by Russian news agencies.
It was the second time that warships have been used since the start of the bombing campaign on September 30.
Moscow has stepped up its strikes in Syria with long-distance bombers after confirming for the first time on Tuesday that a bomb downed a Russian airliner in Egypt last month.
At least eight people were killed in at least 50 air strikes in the eastern Deir Ezzor province today, during which dozens of oil tankers were destroyed, the Syrian Observatory for Human Rights said.
Also Read
Russia has also doubled the number of jets it has based in government-held territory in Syria to 69 over the past few days, Shoigu said.
Putin praised the Russian operation in Syria but said it was "still not sufficient" to wipe out the jihadists in the country and that a "large volume of work" lay ahead.