BEIRUT -- Syrian troops ambushed a large group of rebels Wednesday trudging through what once was a secret route through a desert road northeast of Damascus, killing more than 60 fighters in a barrage of machine gun fire and leaving their bodies in the sand.
State television claimed those killed came from an al-Qaida-linked group that has joined the battle against President Bashar Assad, whose troops are trying to drive opposition forces from areas surrounding his seat of power in the capital.
There were conflicting reports on the attack in Adra, which lies on a supply route between Damascus and rebel-held areas to the east that is often the scene of heavy clashes between the two sides. The dawn attack dealt another heavy blow to opposition troops following a string of recent regime successes.
Syrian troops have been on the offensive in the past few months in an attempt to clear out Damascus suburbs held by opposition fighters.
Syrian state-run media showed footage of bloodied corpses lying on the ground, some wearing camouflage gear with their weapons scattered around in the sand. One picture showed gas masks next to the weapons.
The state-run SANA news agency said "dozens" of rebels were killed in the ambush as they were on their way to attack an army post near Damascus. SANA identified the dead as members of the al-Qaida-linked Jabhat al-Nusra, and said some were foreign fighters.
Broadcaster Al-Ikhbariya also showed a Tunisian passport, Islamic headbands and automatic rifles apparently carried by the rebels.
Some activists disputed the account, saying those killed were Syrian fighters from a mix of brigades delivering aid to besieged areas.
Mohammed Saeed, an activist based near Damascus, told The Associated Press that 65 rebels were on their way from Damascus' eastern suburbs to Qalamoun nearby. Saeed said rebels walked the 19-mile route because it is dangerous to drive in the area as it is watched by Assad's forces.
"It seems that the regime discovered the secret road that the rebels were using," Saeed said via Skype. "The regime forces riddled them with heavy machine gun fire."
He said 62 died and three escaped to Qalamoun.
Another activist said the rebels were on their way to deliver medicine, flour and other foodstuffs to the Eastern Ghouta region, which has been besieged for months. He said the rebels were a "mix of fighters," including some from Nusra Front. He spoke on condition of anonymity out of fears of retribution.
The Britain-based Syrian Observatory for Human Rights said at least 62 rebels died in Wednesday's ambush. It did not report any government casualties.
In the north, a missile struck the rebel-held city of Raqqa, killing three people and wounding dozens including children, the Local Coordination Committees activist group said. The Observatory said that two children were among the three killed.
Amateur videos showed at least three children who suffered wounds and were rushed away in a pickup truck.
A boy, with minor wounds to his mouth, knees and feet, screamed as he was held by a man in the pickup truck and shouted "Dad!" The man holding him tried to calm him down, saying: "Dad will come soon."
The videos appeared genuine and corresponded to other AP reporting on the events depicted.
Wednesday's missile attack came after Human Rights Watch said missiles fired by the Syrian army into populated areas have killed hundreds of civilians in recent months.
Meanwhile, the Observatory said that Kurdish gunmen captured about 70 government troops Wednesday who fled the air base of Mannagh in the northern province of Aleppo. The base was captured by rebels Tuesday after months of fighting.
The Observatory also reported fighting and shelling in the mountains of the coastal province of Latakia, an Assad stronghold. Rebels captured 11 Alawite villages in an offensive earlier this week and troops launched a counterattack to retake it.
Syria's conflict has taken on an increasingly sectarian tone in the last year, pitting predominantly Sunni Muslim rebels against members of Assad's Alawite sect, an offshoot of Shiite Islam.
Syria's crisis started as a largely peaceful uprising against Assad's rule in March 2011. It turned into a civil war after opposition supporters took up arms to fight a brutal government crackdown. More than 100,000 people have been killed in the violence.
The scale of that destruction could be seen in satellite images released Wednesday by Amnesty International. The images showed hundreds of damaged or destroyed houses and more than 1,000 roadblocks around the northern city of Aleppo, which has seen months of vicious fighting.
"Satellite images really speak for themselves," said Donetella Rovera, a senior Amnesty adviser who recently returned from a trip to Aleppo. "You can see really clearly buildings -- groups of buildings -- that were there a year ago that are no longer there today."