A UN aid convoy that was bombed while en route to the besieged city of Aleppo in September came under an air attack, a UN inquiry has concluded, but it was unable to identify the perpetrators.
The board of inquiry found that "while the incident was caused by an air attack, it was not possible to identify the perpetrator or perpetrators," said a summary of the findings released on Wednesday.
The convoy was "subject to an attack from the air, using multiple types of munitions deployed from more than one aircraft and aircraft type," the inquiry found.
At least 10 people were killed and 22 injured in the September 19 attack at Urem al-Kubra, near the northern city of Aleppo, as a fragile ceasefire agreed to by the United States and Russia collapsed.
The board rejected allegations that the attack could have been carried out by direct fire or a ground assault in the rebel-held area.
It noted that Syria and Russia as well as the US-led coalition "all had the capabilities needed to carry out an attack of the kind" that took place that day.
But it concluded the involvement of coalition aircraft was "highly unlikely."
The board said it had received reports that three Syria helicopters and three aircraft were "highly likely" to have perpetrated the attack and that a Russian plane was also suspected of being involved.
"However, the board did not have access to raw data to support these assertions and, in their absence, it was unable to draw a definitive conclusion," it said.
Russia and Syria have denied involvement in the bombing.
The board of inquiry, led by retired Indian general Abhijit Guha, was not allowed to visit the scene of the attack in Urem al-Kubra, but it did travel to Syria in early December.