MOSCOW >> Russians warships in the Mediterranean Sea have fired four cruise missiles at the Islamic State group’s positions in Syria, the Russian defense ministry said today.

The ministry said in a statement that the Admiral Essen frigate and the Krasnodar submarine launched the missiles at IS targets in the area of the ancient city of Palmyra. There was no information on when the missiles were launched.

Russia, a staunch Damascus ally, has been providing air cover to Syrian President Bashar Assad’s offensive on the IS since 2015.

Syrian troops backed by Russian airstrikes captured Palmyra in March last year and Moscow even flew in one of its best classical musicians to play a triumphant concert at Palmyra’s ancient theater. IS forces, however, recaptured Palmyra eight months later before Syrian government troops drove them out again in March this year.

Fighting around Palmyra continues.

Russia’s defense ministry said its statement today that the strikes successfully hit IS heavy weapons and fighters whom the group who had deployed and moved to Palmyra from the IS stronghold of Raqqa, the de facto capital of the Sunni militant group and its self-proclaimed caliphate.

Moscow said it had notified the U.S., Turkish and Israeli militaries beforehand of the upcoming strike. It added that the Russian strike was promptly executed following the order, a testimony to the navy’s high readiness and capabilities.

Russia has been busy mediating between Assad and Turkey and the West who seek his removal. Earlier this month Russia, Iran and Turkey agreed to establish safe zones in Syria, signing on to a Russian plan under which Assad’s air force would halt flights over designated areas across the war-torn country. Russia says maps delineating the zones should be ready by June 4.