Air raids killed 16 people in Syria's Deir Ezzor province Saturday, most of them people gathered at a mourning tent for rebel Free Syrian Army (FSA) officers murdered by jihadists, an NGO said.
Warplanes "bombed the locality of Muhassen six times, killing 16 people, including three women," the Syrian Observatory for Human Rights said.
Observatory director Rami Abdul Rahman said one of the targets had been the tent and that "most of the victims died in that raid."
The Britain-based Observatory said the bodies of the FSA's deputy commander for the area and two other rebel officers had been found Friday on the banks of the nearby Euphrates River near Muhassen.
The three had been captured Wednesday by an Islamist brigade allied with the jihadist Islamic State of Iraq and the Levant (ISIL) and their bodies showed signs of having been killed execution style.
Earlier Friday, ISIL, which has a significant presence in the eastern province on the border with Iraq, had seized Muhassen and two other villages in the area.
Elsewhere in Syria, 21 surface-to-surface rockets hit the suburban Damascus town of Mleiha, which controls access to the rebel-held Eastern Ghouta area, the Observatory said.