Syrian rebels linked to al-Qaeda have seized control of a key airbase in the north-western province of Idlib after long battle, Syrian state TV says.
Abu al-Duhur airbase was under siege for nearly two years by the militants, who have captured most of the province.
The militants behind the attack are believed to be a coalition of Islamist rebels, including the al-Nusra Front.
Since late March, rebels have seized a number of cities in the province including Idlib and Jisr al-Shughour.
In late August, militants used suicide attacks to seize the entrance to the airbase and several positions on its outskirts.
The report on Syrian state TV conceded that government troops had “evacuated their positions and moved to another point”.
With the fall of the airbase the Syrian military has been completely driven out of Idlib province, according to the Britain-based Syrian Observatory for Human Rights.
The activist group said local pro-government militia forces remained in two Shia villages in Idlib province but the army had now fully withdrawn.
Analysis: Sebastian Usher, Arab Affairs Correspondent
This is another blow for President Assad and his overstretched forces, but Idlib was already all but lost to the rebels. The region is now under the control of a mainly Islamist coalition, dubbed The Army of Victory, which includes Al Qaeda’s Syrian affiliate, the Nusra Front.
The coalition’s success has come both from uniting a variety of rebel militias into a single fighting force and a rapprochement of sorts between their main backers, Saudi Arabia, Qatar and Turkey, which has allowed a new flow of cash and weapons.
There are strains, though, within the rebel coalition over the role of the Nusra Front. And even though President Assad faces increasing pressure on a variety of fronts, he can take some comfort in the fact that the regions he has lost are held by different groups that are for now at least as opposed to each other as they are to him.
The loss of the airbase is the latest in a series of setbacks for government forces in the region. Earlier this year, militant groups captured the provincial capital, Idlib city, as well as other towns and villages.
President Bashar al-Assad’s regime has been at war against various rebel groups for the past four years, in a conflict that has so far killed at least 240,000 people.