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 the coalition thought it was hitting ISIS militants, but hours later said the airstrike may have struck Syrian soldiers.
A senior administration official told CNN late Saturday the US relayed its regret through Russia for the “unintentional loss of life.”
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.
The UK-based Syrian Observatory for Human Rights put the death toll at 83 and said at least 120 soldiers were wounded.
A US official told CNN they broadly described the geographic area to the Russians — as is customary — before the strike but did not give a precise location. The coalition thought it was going after an ISIS tank position.
Russia blames the United States
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.
Another US official said the Pentagon trusts the Russian military unit that placed the call informing them of the incorrect target and had little doubt something went wrong.
Syrian troops have been battling ISIS in Deir Ezzor for years, and the Islamist militants control most of the city.
“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.
The UN Security Council was holding an emergency meeting to discuss the airstrikes.
ISIS militants launched an attack on the Syrian position after the airstrikes, Sputnik reported, citing the Russian Ministry of Defense. Syrian state-run news agency SANA said the military was able to regain control of the area ISIS held briefly.
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, SANA reported.
Russia’s Foreign Ministry had similar words, according to spokeswoman Maria Zakharova. She said Russia had concluded the White House is sympathetic to ISIS. She also said that the United States didn’t communicate its intention to carry out operations in the area.
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.
The area in eastern Syria where the airstrike took place is not part of the ceasefire.
The main focus of the ceasefire was to allow humanitarian aid to reach the Syrian people besieged by war. Once the humanitarian relief was in, the Russians and Americans were meant to agree on targeting jihadist factions: Jabhat Fateh Al-Sham, the former al Qaeda affiliate in Syria, and ISIS. To do that, they are supposed to set up a Joint Implementation Center.
CNN military analyst Lt. Col. Rick Francona said it is not clear now what will happen.
“This might put in danger this Joint Implementation Center that the US and the Russians are supposed to set up in the next few days to coordinate just these kinds of strikes against ISIS and to prevent just what happened,” he said Saturday.
Russian Foreign Minister Sergei Lavrov, in a telephone call Saturday with US Secretary of State John Kerry, urged the US military to fully participate in monitoring the Syrian ceasefire and taking action against its violations, according to a statement from the Foreign Ministry.