BEIRUT — Thwarted by aerial attacks, Syrian rebels appear to have begun systemically targeting government air bases and aircraft, while trying to capture antiaircraft missiles that can shoot down helicopters and fighter jets.
An opposition group reported Saturday that insurgents had captured an air defense base in eastern Syria, close to the Iraqi border, and that battles were raging near a military airport in the area. News reports cited opposition sources as saying that some antiaircraft missiles were seized.
It was reportedly at least the third time in a week that rebels had targeted government air installations. The others were near the northern cities of Aleppo and Idlib, close to the Turkish border. If the reports are accurate, the operations demonstrate an elevated degree of coordination among various rebel brigades, which often operate autonomously.
The attacks seem to be directed at bases from which aircraft take off to strike opposition-held territory.
"When you can't hit the airplanes when they are flying, you will make sure they can't take off," said a rebel representative in Idlib province who goes by the nickname Abu Bashir. "There are not enough antiaircraft weapons and missiles, so targeting air bases … is a natural choice."
The government of President Bashar Assad rarely deployed fighter jets and helicopter gunships in the early days of the conflict, now in its 18th month. The military initially relied heavily on tanks, artillery and ground troops. But as insurgent forces grew in strength and attacks became more audacious, the government unleashed its considerable air assets.
Rebels complain about a lack of surface-to-air missiles that could help neutralize military aircraft. There have been repeated reports that the opposition has received some supplies of such weapons, either provided by overseas suppliers, captured from government stocks or purchased on the black market. But there has been no indication of widespread deployment of shoulder-fired surface-to-air missiles in Syria.
Still, in the last week, the opposition has reported downing several aircraft, including a helicopter that was seen in a video Monday falling to the ground in flames in Damascus, the capital. On Thursday, another opposition video posted on the Web appeared to show a downed fighter jet in Idlib province and a pilot parachuting from the aircraft.
The official state news service said authorities repulsed a "terrorist" assault Wednesday on the Taftanaz air base in Idlib province. But a rebel media activist known as Abu Houmam said 10 helicopters were destroyed and six damaged in a surprise attack on the base.
The rebel spokesman described the attack as an intricate operation in which the base was closely observed for weeks and defectors from the facility provided details on operations. The rebels deployed heavy weapons, including mortars, locally manufactured rockets and a captured tank, with an eye to destroying as many aircraft as possible, Abu Houmam said.
A day later, the opposition reported that more helicopters were destroyed in an attack on an air base in Aleppo.
There was no independent confirmation of any of the attacks. Authorities have yet to acknowledge that rebels have shot down any aircraft or destroyed any helicopters or planes on the ground.
Meanwhile, another day of fierce combat was reported Saturday in Aleppo, where rebel and government forces have been fighting for more than a month. Rebels have pulled back from some initial territorial gains, but government forces have not succeeded in dislodging insurgents from the city.
Tens of thousands of civilians have fled and officials have warned of a humanitarian catastrophe in Aleppo, the country's biggest city.
On Saturday, the new United Nations envoy to Syria issued a warning to the Assad government.
"I call on parties inside Syria to halt the fighting. Undoubtedly, this call is primarily directed to the government," the envoy, Lakhdar Brahimi of Algeria, said in New York. "The need for change is urgent and necessary."
Also Saturday, the government and rebels accused each other of a new round of extrajudicial executions. Such charges have become an almost daily feature of the conflict.
The official Syrian news service alleged that "an armed terrorist group" had killed five members of a family in Aleppo's Marjeh district. State news media said a terrorist known as "the captain" headed the faction responsible for the attack.
An opposition organization, the British-based Syrian Observatory for Human Rights, alleged that a dozen people were "summarily executed" in the town of Kfar Batna, outside Damascus.
There was no independent substantiation of either incident.
McDonnell reported from Beirut and special correspondent Marrouch from Antakya, Turkey.