Syrian state media reported on Saturday that two Russian planes carrying around 80 tonnes of humanitarian aids landed in the airport of the coastal province of Latakia, a stronghold of the regime.
Syria has denied reports from media and intelligence sources that Russia, its ally in the five-year-long civil war in the country, has been sending it military support.
Sources says Russia is sending advanced anti-aircraft missiles systems to Syria.
According to Reuters, Two Western officials and a Russian source said that Russia is providing anti-aircraft missiles to Syria as a part of military support for embattled Syrian leader Bashar al Assad.
The system will be operated by Russian troops rather than Syrians according to the officials. One of the sources, a Western diplomat said, "This system is the advanced version used by Russia and it's meant to be operated by Russians in Syria."
According to the Russian source - who is close to the Russian navy - the SA-22 system, known as the Pantsir-S1, was sent to Syria in 2013.
Moscow, an ally of Syria since the Cold War, has a naval base in the Syrian coastal city of Tartus and will likely defend its existence there since it's the only Russian base in the Mediterranean.
The war in Syria started in 2011 after anti-government peaceful demonstrations descended into a civil war between five main factions - the regime, the opposition, al Qaeda-affiliated Nusra Front, ISIS, and the Kurdish People's Protection Units (YPG) militia.
The UN has said that some 250,000 people have been killed and an estimated 7.6 million are internally displaced in Syria. More than 5.4 million others have fled the country into neighbouring Turkey, Lebanon, Jordan, Egypt, Iraq, as well as Europe.
Kerry warns Lavrov
Secretary of State John Kerry on Saturday expressed US concerns over the latest reports indicating Russia is increasing its military presence in Syria to Russian Foreign Minister Sergei Lavrov.
The State Department announced. "The secretary made clear that if such reports were accurate, these actions could further escalate the conflict, lead to greater loss of innocent life, increase refugee flows and risk confrontation with the anti-ISIL coalition operating in Syria."
Some US officials said temporary housing reported to be built by Russia will allow Moscow to deploy up to 1,000 advisers or other military personnel to the airfield that serves Latakia, Syria's principal port city that is near the Assad family's ancestral home.
Speculation has been rising that Russia has effectively expanded its involvement in the Syrian civil war by supplying advanced weaponry, a raft of spare parts for existing machines, and deploying increasing numbers of military advisers and instructors.
As an answer to those speculations, Russia's President Vladimir Putin said that Russia is providing ‘’serious’’ training and logistical support to the Syrian army, which is his first public confirmation of Russia’s involvement in Syria’s civil war.
Putin said, “To say we're ready to do this today - so far it's premature to talk about this. But we are already giving Syria quite serious help with equipment and training soldiers, with our weapons."
He also added that discussion of direct military intervention is ‘’so far premature’.’ but did not reject the idea that such a step could be taken in the future.
One senior Syrian regime military official, who defected in 2012, told the Telegraph that he had worked with Russian officers, but they were experts, not fighters. He also pointed out that most operating rooms were filled by Russians and defence operations were also planned by Russian experts.
"Most of the operations room and many of the defence lines are planned by Russian experts, so there are extra technical personnel now. They are mainly in Damascus,” the defector said, citing former colleagues who are still serving under the Assad government.