As a delicate ceasefire appeared to be holding, the Syrian military said an airstrike Saturday by the US-led coalition hit a regime military position in eastern Syria.
The US military said an airstrike may have struck Syrian soldiers, but the coalition thought it was hitting ISIS militants.
A statement from US Central Command said the coalition conferred with the Russian military before the strike.
“The coalition airstrike was halted immediately when coalition officials were informed by Russian officials that it was possible the personnel and vehicles targeted were part of the Syrian military,” CENTCOM said.
The Russian military said 62 Syrian soldiers were killed near Deir Ezzor Airport, according to the state-run Sputnik News Agency. It quoted Russian Maj. Gen. Igor Konashenkov as saying two F-16s and two A-10s carried out four strikes.
A US official told CNN they broadly described the geographic area to the Russians before the strike but did not give a precise location. The coalition thought it was going after an ISIS tank position.
About 25 minutes into the strike, the Russians called the United States and said coalition forces were hitting Syrian troops, the US official said. The United States immediately withdrew and did not strike other planned targets in that area, the official said.
The United States, for now, doesn’t dispute the claim on how many regime troops were killed.
“Syria is a complex situation with various military forces and militias in close proximity, but coalition forces would not intentionally strike a known Syrian military unit,” CENTCOM said.
Russia blamed the United States for failing to coordinate with them on the airstrikes, a Russian Defense Ministry spokesman told Sputnik.
“If this airstrike was carried out due to an error in the coordinates of the target, it is a direct consequence of (the) US side’s unwillingness to coordinate its actions against terrorist groups with Russia,” Sputnik quoted the spokesman as saying.
ISIS militants launched an attack on the Syrian position after the airstrikes, Sputnik reported, citing the Russian Ministry of Defense.
The London-based Syrian Observatory for Human Rights put the death toll at 83 and said at least 120 soldiers were wounded.
The incident comes during a fragile ceasefire that went into effect Monday. The truce calls for a halt to the violence between the Syrian regime and rebel forces, but it does not cover militant groups considered terrorists, such as ISIS and Jabhat Fateh al-Sham, formerly known as al Nusra Front.
The Syrian military said it viewed the strike as evidence the United States and the coalition support ISIS. It called the incident a serious and blatant aggression, the Syrian state-run news agency SANA reported.
The ceasefire has offered some respite from violence in the civil war, which has killed an estimated 430,000 people since 2011 and touched off an international refugee crisis. But there have been reports of violations, and the Russians have said the United States is not fulfilling its obligations.
Russian Foreign Minister Sergei Lavrov, in a telephone call Saturday with U.S Secretary of State John Kerry, urged the U.S military to fully participate in monitoring the Syrian ceasefire and taking action against its violations, according to a statement from the Foreign Ministry.