Images of the Admiral Makarov and Admiral Grigorovich steaming through the Bosphorus Strait, which links the Black Sea with the Mediterranean, were posted on social media. The vessels, both armed with Kalibr cruise missiles, are heading for the Syrian port of Latakia after last night’s attacked sparked fears of a serious escalation in the conflict.
The reaction on social media was one of anger and astonishment.
One Twitter user said: “So Russian warships are sailing through Turkish waters to bomb Turkish troops!”
Another said: “The Turks should sink them now.”
Under the terms of a 1936 international treaty known as the Montreaux Convention, the Bosphorus – which runs right through the middle of Istanbul – is open to all civilian vessels during peacetime, as well as naval ships belonging to its Black Sea neighbours.
It gives Russia’s Black Sea fleet easy access to the Med and beyond and has been of massive strategic importance in the Syrian conflict.
Russian navy officials confirmed the two frigates from the Black Sea Fleet were en route to the Syrian coast. Both warships have previously taken part in Russia’s offensive in Syria.
They sailed through Istanbul as angry crowds gathered outside the Russian consulate in the city after news of last night’s deadly airstrikes emerged.
Standing in front of a line of riot police and a water cannon, they chanted “murderer Russia, murderer Putin”.
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The attacks came after Turkey-backed Syrian opposition fighters retook a strategic northwestern town from Moscow-backed government forces in the northeastern Idlib province.
Turkey said the airstrikes came despite coordination with Russian officials on the ground and continued despite warnings after the first bombing raids.
Turkish Defence Minister Hulusi Akar said 309 Moscow-backed Syrian government soldiers were killed in retaliation.
Mr Stoltenberg said: “We call on Russia and the Syria regime to stop the attacks, to stop the indiscriminate air attacks.
“We also call on Russia and Syria to fully respect the international law.
“We call on Syria and Russia to fully engage in UN-led efforts to find a peaceful solution for the conflict in Syria.”
Mr Putin and Turkish President Tayyip Erdogan have spoken on the phone and agreed to organise top-level talks to address the situation in Idlib which both men said was a matter of “serious concern”.
Russian and Turkish officials are meeting in Ankara today.