Syrian rebels are closing in on the country's second largest airport, reportedly killing more than 40 soldiers and bringing them closer to what could be their biggest conquest since the beginning of the civil war.
Control of Aleppo international airport and a military air base next to it would be a huge strategic shift for Syria's north-eastern region, giving the opposition a potential air hub enabling aid and other flights.
But activists said it could be days before the rebels would be able to push their way into the airport, seven kilometres (four miles) from the contested city centre.
The country's air space is firmly controlled by the government, which uses its warplanes to bomb rebel strongholds.
The advance on the airport, which stopped handling any flights weeks ago because of the fighting, comes on the heels of other strategic gains.
Rebels this week captured the nation's largest dam and a military base near Aleppo. They have also brought the fight closer to Damascus, seat of President Bashar Assad's regime, moving to within a few miles from the heart of the city.
"There has been some extremely significant advances by the rebels in the past few days. There is real fear and flagging morale among regime forces in the region," said Muhieddine Lathkani, a London-based member of the Syrian National Council opposition group.
The government tried to reverse the gains with a series of air strikes in several locations across the country today.
In Jobar, a rebel stronghold in northeastern Damascus, 13 people were killed in government shelling, according to the Observatory. Fighter jets also carried out air strikes on rebel positions in the central province of Homs, it said.
The rebels have been pushing their way into the capital since last week. The foray marks the opposition's second significant attempt to storm Damascus since July, when the rebels captured several neighbourhoods before being swept out by a swift government counteroffensive.