Two weeks of battles between Syrian rebels and jihadists have killed at least 1,069 people, mostly fighters, the Syrian Observatory for Human Rights said Thursday.
Among the dead, not all of whom were identified, were 608 Islamist and moderate rebels, 312 jihadists from the Islamic State of Iraq and the Levant (ISIL) and 130 civilians, the Britain-based group said.
The battles broke out when rebels launched an offensive mainly in northern Syria against their erstwhile jihadist allies, whose quest for hegemony and systematic abuses have raised the wrath of those fighting President Bashar al-Assad's regime.
Among the 130 civilians killed were 21 who had been summarily executed by ISIL in a children's hospital in Aleppo that the jihadists had turned into a base, the Observatory said.
Others died after being caught in the crossfire or in car bomb attacks launched by ISIL, said the Observatory.
Among the anti-ISIL rebels killed were 99 who were summarily executed by ISIL.
The rebels also executed 56 ISIL members after taking them prisoner, said the Observatory, which relies on a broad network of activists and doctors in Syria for its reporting.
Another 19 people were reported killed in the fighting that has stretched from Aleppo to Idlib, Raqa, Deir Ezzor and Hama provinces in the past fortnight, though the Observatory could not confirm their identities.