The overthrow of Syrian President Bashar al-Assad raises questions about the future of Russian military bases - the Hmeimim air base in Latakia and the Tartus naval facility.
Reuters reported that satellite images on December 13 showed that at least two Antonov AN-124, the world's largest cargo aircraft, at Hmeimim base with the front of the aircraft open, seemingly preparing to load goods.
A Syrian security official stationed outside the facility said at least one cargo plane had flown out on December 14 to Libya.
According to Syrian military and security sources, Moscow is withdrawing troops from the front line and withdrawing some heavy equipment and senior Syrian officers. However, Russia has not withdrawn from its two main military bases and currently has no intention of doing so.
Some equipment is being transferred back to Moscow as well as senior Syrian military officers, but the goal at this stage is to regroup and redeploy according to developments on the ground.
A senior opposition official close to the new interim government told Reuters that the issue of the Russian military presence in Syria and previous agreements between the Assad government and Moscow were not discussed.
"This is a matter for future negotiations and the Syrian people will have the final say," the official said, adding that Moscow had established communication channels.
"Our forces are also close to Russian bases in Latakia," he said without elaborating.
The Kremlin said Russia was in talks with Syria's new leadership about the bases. Moscow is not withdrawing from its bases in Syria, according to a Russian source.
Russian President Vladimir Putin, who intervened in the Syrian civil war in 2015 to support President Assad when the West called for his oustment, has granted the ousted president asylum in Russia.
Russia has supported Syria since the beginning of the Cold War and recognized its independence in 1944 when Damascus sought to overthrow French colonial rule.
Syrian bases are an indispensable part of Russia's global military presence: Tartus naval base is Russia's only repair and supply hub in the Mediterranean, while Hmeimim air base is a key transit station for military operations in Africa.
Russia also has listening stations in Syria that are operated alongside Syrian signal stations, according to Western intelligence sources and the Syrian military.
Tartus base dates back to 1971 and Moscow was granted a 49-year, free lease in 2017 after Russia intervened in the civil war to help Assad.
Yoruk Isik, a geopolitical analyst in Turkey, said Russia may have sent cargo aircraft out of Syria via the Caucus, then to the Al Khadim air base in Libya.
In Hmeimim, Reuters saw Russian soldiers walking around the base as usual and fighter jets in the aircraft storage.
Satellite imagery taken by Planet Labs on December 9 shows at least three ships in Russia's Mediterranean fleet - two guided missile torpedoes and one tanker - anchored about 13 km northwest of Tartus.
