MOSCOW, May 31 (Xinhua) -- A frigate and a submarine of Russia in the eastern Mediterranean have fired four Kalibr missiles at the Islamic State (IS) targets near Palmyra in Syria, the Russian Defense Ministry said Wednesday.

The Admiral Essen frigate and Krasnodar submarine launched four Kalibr cruise missiles from the eastern Mediterranean against the IS positions with heavy equipment and militant manpower transferred from Raqqa, the IS stronghold in northern Syria, the ministry said in a statement.

The statement also said Russia had informed the U.S., Turkish and Israeli military forces of the strike in advance.