Commanders of the Russian group of forces in Syria has taken measures to avert the withdrawal of the Islamic State militants from Raqqa towards Palmyra, which is located to the south, a source at the Russian Defense Ministry said, TASS reports.

"The data confirmed via several independent channels suggests that the commanders of Kurdish units affiliated with the so-called Syrian Democratic Forces and the leaders of the Islamic State detachments operating in the area reached an agreement on the opening of the so-called secure southern corridor," the source said.

"The terrorists have received an opportunity for unimpeded withdrawal on the condition they will head towards Palmyra," he said.

Upon receiving the data, the command of the Russian forces in Syria took steps to prevent the militants’ withdrawal southwards, the source said.