There have been frequent clashes in Aleppo
Rebels fighting to overthrow Syrian President Bashar al-Assad have captured a key airbase in Aleppo province, near the Turkish border, activists say.
The pro-opposition Syrian Observatory for Human Rights (SOHR) said rebels took Menagh airport early on Tuesday.
The opposition has been trying to capture the base since last year.
Jim Muir, the BBC's correspondent in Lebanon, says the base lies on a major rebel supply route from Turkey.
Rebels have also recently taken several villages in Latakia province, the heartland of President Assad's minority Alawite sect.
But loyalist forces have made recent gains too - in the cities of Damascus and Homs, and other areas of Aleppo.
As the battle at Menagh was raging, the government celebrated its own victory in the central city of Homs as the defence minister toured the Khalidiyeh neighbourhood which was recently retaken from rebel control.
More than 100,000 people have been killed in the 28-month conflict in Syria, with a further 1.7 million Syrians forced to seek shelter in neighbouring countries, according to UN estimates.
The Menagh airbase, north of Aleppo, is isolated in rebel-held territory and had been under siege since last December.
Rebels gradually captured most of the sprawling base in recent months, leaving only about 70 loyalist troops pinned down in the command headquarters.
Our correspondent says the final push, carried out by at least nine different rebel groups, began with a suicide bomb attack on the headquarters, reportedly by a Saudi militant.
At least 10 rebels are reported to have died in the fighting, and some of the government troops are also said to have been killed, with others captured.
On Sunday rebel forces also captured a series of Latakia villages, after attacking government outposts with anti-tank missiles in the Jabal al-Akrad hills. The move brings them closer to Mr Assad's hometown of Qardaha.
The SOHR said troops and rebels had been engaged in fierce fighting in Latakia for two days.
The Latakia region represents the political heartland of the Alawites, who make up about 10% of Syria's Sunni-dominated population.