Russian warplanes bombed a camp run by rebels trained by the CIA, the group’s commander said, putting Moscow and Washington on opposing sides in a Middle East conflict for the first time since the Cold War.
The US and Russian militaries held talks via video link to seek ways to keep their militaries apart as they wage parallel campaigns of air strikes in Syria, a US defence official said.
Russian jets struck targets near the cities of Hama and Homs in western Syria on the second day of their surprise air campaign, which they launched on Wednesday.
Moscow said it had hit IS positions, but the area where it struck is held by a rival insurgent alliance, which unlike IS is supported by US allies including Arab states and Turkey.
Hassan Haj Ali, head of the Liwa Suqour al-Jabal rebel group, said one of the targets was his group’s base in Idlib province, struck by around 20 missiles in two sorties.
His fighters had been trained by the CIA in Qatar and Saudi Arabia, part of a program Washington says is aimed at supporting groups that oppose IS and Assad.
“Russia is challenging everyone and saying there is no alternative to Bashar,” Haj Ali said. He said the Russian jets had been identified by members of his group who once served as Syrian air force pilots.
Two Lebanese sources said hundreds of Iranian troops had reached Syria in the past 10 days with weapons to mount a major ground offensive. They would also be backed by Assad’s Lebanese Hezbollah allies and by Shia militia fighters from Iraq, while the Russians would provide air support.
“The vanguard of Iranian ground forces began arriving in Syria: soldiers and officers specifically to participate in this battle.
“They are not advisers ... we mean hundreds with equipment and weapons. They will be followed by more,” one of the sources said.
Russia’s sudden decision to join the war with air strikes on behalf of Assad, as well as the increased military involvement of Iran, could mark a pivotal turning point in a conflict that has drawn in most of the world’s military powers.
With the US leading an alliance waging an air war against IS fighters, the Cold War superpower foes Washington and Moscow are now engaged in combat over the same country for the first time since World War Two.
They say they have the same enemies, the IS group of Sunni Muslim militants who have proclaimed a caliphate across eastern Syria and northern Iraq.
But they also have very different friends, and sharply opposing views of how to resolve the four-year-old Syrian civil war, which has killed more than 250,000 people.
Washington and its allies oppose IS and Assad, believing he must leave power in any peace settlement.
Washington says a central part of its strategy is building “moderate” insurgents to fight against Assad and IS, although so far it has struggled to find many fighters to accept its training.
Moscow supports the Syrian president and believes his government should be the centrepiece of international efforts to fight extremist groups.
It appears to be using the common campaign against IS as a pretext to strike against groups supported by Washington and its allies, as a way of defending a Damascus government with which Moscow has been allied since the Cold War.
The Russian strikes represent a bold move by President Vladimir Putin to assert influence beyond his own neighbourhood: it is the first time Moscow has ordered its forces into combat outside the frontiers of the former Soviet Union since its disastrous Afghanistan campaign in the 1980s.
In the second day of strikes, Russia said it launched eight sorties with Sukhoi warplanes overnight, hitting four IS targets. However, none of the areas where it said the strikes took place is held by IS.
Al-Mayadeen, a pro-Damascus television channel based in Lebanon, said the jets carried out at least 30 strikes against an insurgent alliance known as the Army of Conquest.
The alliance includes the Nusra Front, al-Qaida’s Syrian branch, but not IS.
The Russian and Iranian intervention in support of Assad comes at a time when momentum in the conflict had swung against his government and seem aimed at reversing insurgent gains.
“The Russian strikes are a game changer. Damascus is off the hook,” a diplomat tracking Syria said.
The Army of Conquest in particular has been advancing against government forces in north-western Syria, supported by regional countries that oppose both Assad and IS.