WASHINGTON • A string of miscommunications, intelligence shortcomings and human errors resulted in a United States-led coalition air strike in Syria that reportedly killed around 90 regime forces, the Pentagon said.
American, Australian, British and Danish planes all took part in the massive air strike in September, which saw a total of 34 guided bombs and hundreds of rounds of high-calibre ammunition blasted at what were believed to be Islamic State in Iraq and Syria (ISIS) targets.
There were "errors in the development of intelligence, as well as missed opportunities for coalition members on duty to recognise and voice contrary evidence to decision makers", US Central Command (Centcom) said.
The statement, which followed a six-week probe, marked the US military's first formal admission of fault in the Sept 17 attack near Deir Ezzor. The strike was conducted by F-16 and FA-18 fighters, A-10 ground-attack craft and drones.
The US-led coalition is focused on attacking ISIS in Syria and Iraq, and is eager to avoid getting involved in Syria's brutal civil war.
Regime officials have accused the coalition of intentionally killing its troops, but Centcom stressed the attack was conducted in "good faith" that it was targeting ISIS.
US Air Force Brigadier-General Richard Coe, who investigated the case, said the probe had only conclusively counted 15 deaths, but acknowledged the toll was possibly much higher. The Syrian Observatory for Human Rights monitoring group has said at least 90 regime troops were killed.
The targets struck included "defensive fighting positions" - vehicles, tents, tunnels and people - all of which were thought to be legitimate ISIS targets. "In this incident, we made an unintentional, regrettable error primarily based on human factors in several areas in the targeting process," Brig-Gen Coe said.
An intelligence analyst spotted a tank in the region north of Deir Ezzor's airfield and concluded that the vehicle "can't possibly" belong to ISIS. But his assessment was overlooked or countered as ISIS had been able to commandeer a regime tank earlier.
The belief that the tank was in ISIS hands led intelligence experts to erroneously assume the areas it was operating in and troops it interacted with were all militants, a mistake known as "confirmation bias".
Further complicating matters, the troops being monitored were not wearing recognisable military uniforms or carrying identifying flags, Brig-Gen Coe said.
A critical miscommunication occurred when Russian forces called the coalition to tell them the strike was hitting Syrian regime troops. That call was subject to a 27-minute delay as the officer with whom the Russians normally spoke was not immediately available. During that window, almost half of the separate strikes making up the larger assault occurred. As soon as the Russians spoke to their regular point of contact, the strike was called off.
No coalition forces have been charged in the incident, and the Pentagon has expressed regret but has not apologised to the Syrian regime.