Free Syrian Army fighters try to locate snipers loyal to Syria's President Bashar al-Assad in Bab al-Nasr district in the old city of Aleppo on Tuesday. (MUZAFFAR SALMAN/REUTERS)

— Syrian rebels have received an unexpected windfall in the form of large weapons caches seized in fighting during the past three weeks, including stocks of heavy arms that could help offset recent battlefield gains by government forces, U.S. and Middle East officials say.

The weapons include hundreds of advanced anti-tank missiles captured in fighting near Damascus and a sizable haul of armored vehicles, machine guns and rockets taken from a Syrian air base overrun this month, the officials said.

While Syria’s fractious rebel brigades regularly acquire arms by looting captured government installations, the arsenals seized in the past month were unusual in size and quality and could help chip away the government’s significant military advantage in some heavily contested parts of the country, according to two Middle Eastern officials and one U.S. official with access to sensitive intelligence on Syria.

The air base was overrun by a force of Western-backed rebels and radical Islamists. They split the seized materiel, the officials said.

Meanwhile, the rebels have yet to receive promised military aid from the United States and there are no clear signs of a momentum shift in the conflict, which in recent months has seen rebel units driven from former strongholds in several parts of the country, the officials say.

(The Washington Post)

Analysts say the capturing of the Menagh air base north of Aleppo on Aug. 6 did provide a tactical and psychological boost for the rebels, who entered the facility after a costly 10-month siege and carted away truckloads of booty. Rebel commanders are now redeploying newly re-armed units against other strategic targets around Aleppo, the country’s largest city, the officials said.

“The seizing of Menagh is looking very important because the rebels gained a lot of weapons there,” said a senior Middle Eastern intelligence official who spoke on the condition that his name and nationality be withheld, citing the sensitivity of his government’s intelligence collection efforts in the region. “The Syrians were using the air base for weapons storage, and it had a lot of good-quality stuff.”

Jeffrey White, a former analyst for the Pentagon’s Defense Intelligence Agency, called the seized caches larger than usual and said they “will definitely help the rebels, particularly in the Aleppo area,” where government efforts to roll back the resistance appear to have stalled.

Rebel groups, he said, “are making slow progress in taking government-held positions,” particularly in the north, said White, now a defense fellow with the Washington Institute for Near East Policy, a nonpartisan think tank. “It’s no blitzkrieg, but it’s slow, grinding progress.”

Rebels have been less successful in Syria’s coastal provinces, where an offensive against government-held villages near the port city of Latakia has been driven back in recent days. A U.S. official privy to intelligence reports from Syria said both sides appeared to be “drained but resilient.”

“Despite some recent tactical opposition gains, the strategic momentum hasn’t yet shifted back” in the rebels’ favor, said the official, who insisted on anonymity in describing intelligence assessments.

While the rebels remained badly outgunned, the recently seized weapons caches could provide at least a partial answer to new supplies of tanks, aircraft and artillery acquired by the Iran- and Russia-backed government of Bashar al-Assad, U.S. and Middle Eastern analysts say.

During an early-August raid on an army depot in a Damascus suburb, rebel militias acquired hundreds of wire-guided anti-tank missiles, including French-made Milans and Russian Konkurs, analysts confirmed. Videos posted on YouTube showed gleeful rebels hauling away boxes of missiles as well as rocket-propelled grenades. Weapons experts say the highly accurate missiles are capable of destroying any tank in the Syrian military’s inventory.

Within days of that event, a combined force of Islamist and Free Syrian Army rebel units succeeded in overrunning the defenders of the Menagh air base after crashing though the perimeter wall with an armored personnel carrier packed with explosives.

An inventory of seized weapons from the airfield, pieced together by intelligence officials and independent military analysts, includes the equivalent of an armored company’s contingent of T-72 tanks and BMP-1s, Russian-built amphibious fighting vehicles armed with an anti-tank gun and a heavy machine gun. Also seized was at least one 57mm antiaircraft gun and crate after crate of machine guns, grenade launchers and assault rifles, many of them new and in their original packing, the analysts said.

Videos posted on YouTube showed rebel soldiers in camouflage uniforms digging through green boxes filled with missile launchers, artillery shells and ammunition. One rebel commander who participated in the fight played down the overall significance of the cache and declined to give numbers of weapons seized. But he said the fighters were making good use of the materiel.

“It will be distributed between all the different groups that joined in liberating the airport,” said Col. Abdul Jabbar Akaidi, head of the rebel military council in Aleppo.

Loveday Morris and Ahmed Ramadan, both in Beirut, contributed to this report.