BEIRUT A new rebel group boasting about 1,000 fighters launched an operation Sunday to capture Syrias largest city, Aleppo, while government troops using helicopter gunships and heavy artillery rolled back opposition gains in the capital, Damascus.
The spread of fighting into a second major metropolis displayed the rebels growing confidence even though they still cant hold ground against the governments heavy weapons, pushing Syrias civil war toward a new phase of destructive urban combat.
On Sunday, however, a group calling itself the Brigade of Unification announced in an online video that it was launching an operation in Aleppo, Syrias most populated city and a key commercial hub that has remained relatively quiet throughout the uprising.
We gave the orders to march on Aleppo with the aim of liberating it, said Col. Abdul-Jabbar Mohammed Akidi, one of the groups leaders.
The push into Aleppo comes after weeks of high-level military defections, soaring death tolls, fierce fighting near President Bashar Assads seat of power and a bomb blast that killed four top players in his regimes efforts to crush those seeking to end his rule. Rebels also captured several border crossings with neighboring Iraq and Turkey. The oppositions momentum put the regime on the defensive for the first time in the 16-month conflict.
But while the gradual swelling of their ranks and increasing organization have allowed them to push into major cities, they remain largely unable to hold ground against Assads forces and helpless before his helicopters.
The weeks violence pushed the death toll for the uprising to more than 19,000, according to the Britain-based Syrian Observatory for Human Rights. The group said July is likely to be the conflicts deadliest month so far, with more than 2,750 people killed in the first three weeks nearly as many as in the previous month.
More than 100 people were killed Sunday, it said, including at least 24 government troops.
The escalating fighting is also feeding fears that Syrias war could spill across borders and spark a regional conflagration. Assads regime is a bridge between Iran and the Lebanese Shiite militant group Hezbollah.
On the other side, the uprising is largely driven by Syrias Sunni Muslim majority, which has more natural links with the regions Sunni nations such as Saudi Arabia.
Complicating matters, almost all hate Israel the closest U.S. ally in the Middle East.