The U.S. strike in Syria on forces supporting the government of Bashar Assad last week killed several Russian mercenaries, according to multiple reports.
Bloomberg, citing an unnamed U.S. official and three Russians, reported Tuesday that “scores” of Russians were killed in last week’s strike in Deir ez-Zour province.
Two of the Russians told Bloomberg that than 200 mercenaries, mostly Russian, were killed in the strike. The U.S. official put the death toll at 100, with 200 to 300 injured.
If those numbers hold, it could be the deadliest clash between citizens of the United States and Russia since the end of the Cold War.
Russian media was also reporting that several private Russian military contractors were killed in the strike, according to The Associated Press, which added that Kremlin spokesman Dmitry Peskov refrained from comment.
The reports follow one from Reuters on Monday, where former associates of two of the Russians killed identified them to the news wire.
On Wednesday, U.S. forces struck pro-Assad forces after they started what the U.S. military described as an “unprovoked” attack on the U.S.-backed Syrian Democratic Forces.
Pro-Assad forces and U.S.-backed forces have been converging in the Middle Euphrates River Valley, where the last remaining pockets of Islamic State in Iraq and Syria (ISIS) fighters lay.
The Pentagon has not confirmed the composition of the pro-Assad forces involved in Wednesday’s incident, but reports previously said Russian mercenaries were among the group.
On Thursday, Defense Secretary James Mattis described the attack as “perplexing.”
“It’s perplexing why they would do it,” Mattis said. “They have nothing to gain by fighting us. There’s ISIS to be fought. It doesn’t make sense, and I think that’s probably why the Russians, too, at least appear to be perplexed by it.”
He and other Pentagon officials have also maintained that the deconfliction line the United States and Russia operate to prevent clashes in Syria was successfully used, as Russian government forces were not involved in the attack.
But he would not comment on whether Russia has influence over the forces that did attack.
“I’m not willing to say that,” Mattis said. “I don’t know if it’s the same influence. And this is a group that’s off on its own agenda. I’m not willing to say that the Russians have lost influence or gained influence.”