At least 62 rebel fighters have been killed in a Syrian army ambush at dawn near the town of Adra, east of Damascus, said the Syrian Observatory for Human Rights, a monitoring group opposed to President Bashar al-Assad.
The Syrian military said on Wednesday that those killed were members of the al Qaeda-linked al-Nusra Front.
"At least 62 rebels fell as martyrs, most of them youths, and eight others are missing after an ambush by regime forces at dawn near the industrial city of Adra," northeast of the capital, the UK-based monitoring group said.
A Syrian military source quoted by state news agency Sana said the "army carried out an ambush on a group of terrorists belonging to the Al-Nusra Front that was trying to infiltrate Eastern Ghuta and attack a military post".
"All the terrorists were killed and their arms captured," the source added, without giving a toll.
Adra, 35km from Damascus, is the gateway to Eastern Ghuta, a farming region where a large number of rebels are located.
On July 21, 49 rebels were killed in fighting with forces loyal to Assad in Adra, the Britain-based Observatory said.
Syrian troops have been on the offensive in the suburbs of the capital in the past few months in an attempt to protect President Assad's seat of power.
More than 100,000 people have been killed since Syria's conflict started in March 2011 as largely peaceful protests against Assad's rule.