Syrian activists say nearly 500 people, including 85 civilians, have been killed in fighting among Syrian rebels and hardline Islamist State of Iraq and the Levant, or ISIL.
The Syrian Observatory for Human Rights said Friday that 482 people have been killed in the seven days during intense clashes in Aleppo, Idlib, and Raqqah provinces. Of the 85 civilians, it said 21 were executed by ISIL fighters and the rest were killed in crossfire.
The Observatory said 240 combatants from Islamist and non-Islamist rebel battalions were killed in violent clashes, car bombings, or other attacks on vehicles in Aleppo, Raqqa, Hama, and Idlib. It said more than 20 people were executed by the ISIL in Aleppo.
The group also said 157 ISIL fighters died in the fighting, including 47 who were executed by rebels.
Meanwhile, the Syrian government's SANA news agency said Friday the army killed 37 rebels, who it refers to as terrorists, as they tried to leave an area north of the central city of Homs, which is surrounded by the army.
Neither SANA nor the Britain-based Observatory gave figures on government casualties.
Forces loyal to Syrian President Bashar al-Assad have for months surrounded Homs - Syria's third-largest city - which was a center of the opposition uprising against his rule.
Assad loyalists are fighting a fractured opposition force, which has in recent days seen increased clashes between its Islamist and Western-backed elements.