BEIRUT — More than 150 Syrian rebel fighters were killed Wednesday in an ambush by pro-government forces outside Damascus, according to official and opposition accounts.
The casualty toll appeared to be one of the largest in a single operation reported during much of the almost 3-year-old war.
The operation was part of a military push to deny rebels proximity to Damascus, President Bashar Assad's seat of power.
Though initially appearing in state media, accounts of Wednesday's attack and the high death toll were later reported by the Syrian Observatory for Human Rights, a Britain-based, pro-opposition monitoring organization.
The group put the death toll at 152 fighters, mostly members of "Islamic battalions" and Al Nusra Front, an Al Qaeda-linked rebel faction. The observatory said the ambush was carried out by the combined forces of the Syrian army and Hezbollah, the Lebanese group that has dispatched militiamen to Syria to fight alongside government troops.
The official Syrian news media said the ambush resulted in the deaths of more than 175 "terrorists," the government's term for armed rebels. Scores of rebels were injured, they reported.
The dead included fighters from Saudi Arabia, Qatar and the Russian republic of Chechnya, the state news service said. Thousands of Islamist fighters from across the globe have traveled to Syria to join the rebel movement, according to Western intelligence officials.
[Updated 5:20 p.m. PST, Feb. 26: Al Manar, the official televsion channel of Lebanon's Hezbollah movement, aired a video clip that it said showed the doomed rebel fighters moving on foot in a single file before a massive explosion detonated in their midst. The video and other accounts from pro-government media indicate that the rebels walked into a trap. The path they took seems to have been mined, suggesting that the Syrian military may have had advance word of the rebels' intended movement. Al Manar's account said the Syrian army "shot dead" rebels who survived the blast and tried to flee.]
In recent months, Syrian forces have been methodically pushing opposition fighters away from Damascus and other strategic areas. The heavily defended capital has been relatively quiet as fighting has concentrated in outlying zones.
The U.S.-backed Syrian opposition, meanwhile, has been caught up in deadly infighting that has cost the lives of hundreds of rebel fighters since January. Still, large swaths of Syria remain out of the control of the over-stretched military.
After years of fighting, some Damascus suburbs have largely been reduced to thinly populated expanses of rubble-strewn streets and bombed-out buildings. But many heavily damaged suburbs are still contested zones between government and rebel forces.
Wednesday's ambush occurred in a rural stretch of the so-called eastern Ghouta area, a sprawling, mostly rebel-held district to the east and south of the capital, Damascus. The vast area long has been a stronghold of Islamist rebel brigades.
Government forces have been "tightening the grip" on eastern Ghouta "to prevent terrorists from entering into it," said the official Syrian Arab News Agency. The semi-rural area contains many potential infiltration points, however, making it difficult to seal off completely.
State media showed grisly photographs of rows of dead "terrorists," as they called the bodies, sprawled along a dirt road amid bushes in an arid strip of land. The attack reportedly took place in the Otaiba region, long a point of infiltration for rebels seeking to approach the capital.
Soldiers acted on intelligence, state media reported, but further details were not available.