Syria's army captured an airbase in eastern Aleppo from the Islamic State group on Saturday, after more than two months of fierce clashes, a military source and monitor said.
The Jarrah airbase had been under IS control since January 2014, when the Islamist militants seized it from rebels who had captured it a year earlier.
"Regime forces took control of the Jarrah military airport after heavy fighting," said Rami Abdel Rahman, director of the Syrian Observatory for Human Rights monitor.
"The majority of the jihadists have withdrawn, and regime forces are carrying out clearing operations in the airport and engaged in limited clashes with remaining IS elements," he added.
Syria's army launched an offensive against IS in eastern Aleppo province in mid-January, backed by ally Russia.
So far it has taken control of more than 170 villages and towns in the area, according to the Britain-based monitor.
A military source, speaking on condition of anonymity, also confirmed the capture of the military base.
"The Syrian army has completed its capture of Jarrah airport and a number of the surrounding villages," he told AFP.
"It will continue its advances into the areas held by the terrorist organisation and... expand the areas it controls in eastern Aleppo province," he added.
The next key target for government forces in the area will likely be the town of Maskana, on the edge of Lake Assad.
Syria's army is just one of the forces battling IS in the country.
An alliance of Syrian Kurds and Arabs is also fighting the group further east, in Raqa province, with support from the US-led coalition.
More than 320,000 people have been killed in Syria since the conflict began in March 2011 with anti-government protests.