Observatory says death toll including Islamic State fighters is at least 54, with US-led coalition thought to be behind the attack
At least 28 people were killed in an air strike late on Thursday which hit an ice factory near a village still controlled by the Islamic State (IS) group in Syria's eastern province of Deir Ezzor, according to an activist group.
The British-based Syrian Observatory for Human Rights said the total death toll, including IS fighters, was at least 54. The group said it was unclear who had carried out the strike near the village of al-Soussa, close to the Iraqi border.
Both the Iraqi air force and the US-led international coalition that has been fighting IS in Syria and Iraq since 2014 have carried out previous air strikes in the area.
Syria's SANA state news agency said the coalition was responsible for the strike and said more than 30 people had been killed.
Colonel Sean Ryan, a spokesman for the U.S.-led coalition, said that it or "partner forces may have conducted strikes in the vicinity". The coalition would assess the report alleging civilian casualties, he added, in an emailed response to a question from Reuters.
"We have no further information at this time," he added.
IS militants in al-Soussa are squeezed between Russian-backed pro-Syrian government forces, which control the west bank of the nearby Euphrates river, and US-backed Syrian Democratic Forces to the east.
Pro-government forces regained Deir Ezzor city, as well as nearby oil and gas fields, from IS last November as part of a campaign that has seen it assert its control over much of the east of the country.
The militant group had held most of the city since 2014, except for one large pocket where Syrian army troops and 93,000 civilians were under siege for three years.
Pro-government forces have also made gains in southern Syria in the past few days and on Thursday raised the Syrian government flag in Daraa, where protests against Syrian President Bashar al-Assad's rule began in 2011.