- Reports suggest high number of casualties in Deir Ezzor region
- US officials say airstrikes carried out against pro-regime force
Scores of Russian mercenaries were reportedly killed when US forces carried out air strikes against a pro-regime force in eastern Syria last week, according to US and Russian reports.
If the high estimates of Russian casualties are confirmed, it would be the most lethal clash between US and Russian citizens since the end of the cold war, and it comes at a time when proxy forces in Syria are increasingly coming into contact, as they compete for territory vacated by retreating Islamic State militants.
Bloomberg News quoted Russian sources as saying as many as 200 Russian nationals could have been killed in a clash last Wednesday and Thursday around the oil fields of Deir Ezzor region between forces loyal to Bashar al-Assad and a Kurdish-led opposition force supported by US advisers.
The New York Times said that Russian and Syrian officials had estimated that dozens of Russians had been killed.
US Central Command said on Tuesday that US forces came under fire from a tank, and that they responded with three hours of intense strikes from drones and B-52 bombers against the attackers, which it described as a unit of 300 to 500 fighters.
Air force Lt Gen Jeffrey Harrigan said US advisers had been in an operating base alongside units of the mostly-Kurdish Syrian Democratic Forces (SDF) in the course of anti-Isis operations, when they came under tank fire. He added that the senior officer at the base called in airstrikes in response.
Harrigan said the attacking forces were fighting on the side of Bashar al-Assad’s regime, but said he would “not speculate on the composition of this force, or whose control they were under”.
He said: “This…