State media in Syria says army troops have killed 175 rebels in an ambush south of the capital, Damascus.  

Syrian state news agency SANA reported Wednesday that the attack happened at dawn in the opposition-held area of eastern Ghouta.  

SANA quoted a field commander in the area saying most of rebels belonged to the al-Qaida-linked Nusra Front rebel group.

The Britain-based Syrian Observatory for Human Rights also reported the killings, saying that 70 rebels were killed in Wednesday's assault.

The Observatory, which has been documenting Syria's nearly 3-year-old conflict by relying on activists' reports on the ground, says the number of those killed likely will rise because 89 rebels have been reported missing.