Police Col. Ahmed Muse says the bomber struck the 12th April Army Brigade base near the newly reopened sports stadium in Warta-Nabadda district.
The India-China face-off on the Himalayan heights has entered the fifth month. Several rounds of talks at military and diplomatic levels have not led to disengagement at any of the several points where soldiers of the two sides are facing each other.
An independent report published last week in redacted form said there was evidence that 39 unarmed Afghan prisoners and civilians were killed by 19 Australian soldiers.
Three other soldiers were killed in the same manner few days after. Their death makes it 50 French soldiers that have died in Mali since the French intervened in 2013.
The ambush late on Sunday resulted in the deaths of eight soldiers, four allied fighters and three civilians, the Britain-based Syrian Observatory for Human Rights said, updating an earlier toll.
According to Deir Ezzor residents and intelligence sources quoted by Reuters, there has been a rise in recent months of ambushes and hit-and-run attacks by Daesh militants who hide in caves in the mainly desert region.
The Israeli air force carried out more than 18 strikes against multiple targets in an area stretching from the eastern town of Deir Ezzor to the Boukamal desert at the Syrian-Iraqi border, according to the Britain-based war monitor.