The strike occurred on a post of the Syrian Arab Army in the village of al-Hari, east of al-Boukamal – on the banks of the Euphrates River, between al-Boukamal city and the border with Iraq.
A military source told SANA news that a number of people were killed and wounded.
The Syrian Observatory for Human Rights said that at least 38 pro-regime forces were killed, but has not been able to identify who was responsible, AFP reported.
Coalition spokesperson Col. Sean Ryan said they are aware of the reports, but that the coalition had not carried out any strikes in the area, AP reported.
Be careful of misinformation: @CJTFOIR did NOT conduct strikes near Abu Kamal west of the Euphrates. #SDF and the #Coalition is focused on #defeatDaesh mission east of the river.
— OIR Spokesman (@OIRSpox) June 18, 2018
The river has served as a rough frontier between forces loyal to the Syrian regime and those of the US-backed SDF, both fighting ISIS in Deir ez-Zor province.
A deconfliction line between the US and Damascus ally Russia has largely prevented run-ins between the two, though there have been occasional, deadly incidents causing casualties on both sides. In April, brief clashes broke out between them.
Regime forces are fighting off a fierce ISIS offensive in the Deir ez-Zor desert.
ISIS militants mobilized on two fronts – the west banks of the Euphrates River between al-Boukamal and al-Mayadin and further south in the desert, according to the Observatory. The militant group is using a large number of weapons they seized from the army in al-Boukamal.
At least 11 regime forces and militias loyal to them have been killed as well as some 20 ISIS fighters in the operation, according to the UK-based conflict monitor, with government forces achieving some advances on Sunday.
Updated at 1:07 pm
