Syria's official news agency says that an attack on a passenger bus travelling in the country's south has left 28 people dead and others wounded.
The ambush took place along a main highway in Syria's Deir al-Zor province that borders Iraq, Syrian state media said on Wednesday, an incident that residents and defectors say was an ambush on an army vehicle.
State news agency SANA described the incident as a "terrorist attack".
There are few details on the incident in an area where mostly Syrian army and Iranian-backed militias are based, near the ancient city of Palmyra.
A senior military defector in the area said the vehicle was carrying soldiers and pro-government militias who had finished their leave and were on their way back to base in the desolate, sparsely populated area.
Deir al-Zor residents and intelligence sources say there has been a rise in recent months of ambushes and hit-and-run attacks by remnants of Islamic State militants who hid in caves in the mainly desert region.
They also say in the last few months, Arab tribes who inhabit the area have been angered by executions by Iranian militias operating in the area of dozens of nomads suspected of affiliation to militants.