Russian Defence Minister Sergei Shoigu said Tuesday that the military had launched strikes in Syria for the first time from a submarine stationed in the Mediterranean.

"We used Calibre cruise missiles from the 'Rostov-on-Don' submarine from the Mediterranean Sea," Shoigu told President Vladimir Putin, Russian news agencies reported.

Shoigu added that Russian strikes launched on Tuesday had been aimed at "two terrorist strongholds" around Raqqa, the de facto Syrian capital of ISIS.