The Kremlin said on Monday that no final decisions had yet been taken on the fate of Russia's military bases in Syria and that it was in contact with those in charge of the country.

The Tartus naval base and Hmeimim air base are Russia's only military outposts outside the former Soviet Union and have been key to the Kremlin's activities in Africa and the Middle East.

The ousting of Moscow's long-time ally Assad in a shock rebel offensive has brought their future into question.

"There are no final decisions on this," Kremlin spokesman Dmitry Peskov told reporters on Monday.

"We are in contact with representatives of the forces that now control the situation in the country," he added.

Four Syrian officials told Reuters over the weekend that Russia is pulling back its military from the front lines in northern Syria and from posts in the Alawite Mountains but is not leaving its two main bases after the fall of President Bashar al-Assad.

Russia said on Sunday it had evacuated some diplomatic personnel in Damascus as well as Belarusian and North Korean diplomats via a special Russian air force flight from its Khmeimim air base.