The Syrian army is edging its way towards southeastern Aleppo as it battles rebel fighters for control of the northern city, a monitor and a pro-government daily said Tuesday.
The Syrian Observatory for Human Rights said it was a "limited advance" but the first by government troops in more than a year, and that residents fearing a major operation were fleeing the region.
The troops have gained some ground in Aleppo in the past few weeks, taking advantage of the fact that rebels who hold larges swathes of territory have turned their guns against Islamist fighters.
"The Syrian army made a limited advance, for the first time in more than a year, and seized the Karm al-Qasr district on the southeastern fringes of Aleppo," held by the rebels, said the Observatory.
The offensive was launched from Nairab military airport east of Aleppo, Syria's second city and pre-war commercial hub.
A newspaper, which is close to President Bashar al-Assad's government, said the troops made the advance on Monday and also seized the districts of Ballura and Kasr al-Tarrab.
It too said the operation had been launched from Nairab airport in the east, as well as Aziza village in the south, while adding it had reached the outskirts of Mayssar, a rebel bastion in southeast Aleppo.
The Observatory said residents of Mayssar, nearby Marjeh and Enzarrat were fleeing their homes for "neighbourhoods controlled by regime forces... because of the fighting".
The daily also reported the exodus.
Since December 15, Aleppo has been the target of an aerial offensive that has killed hundreds, mostly civilians.
On Tuesday at least three people were killed in regime air raids that targeted Qadi Askar and Mayssar, said the Observatory.
On Saturday, Aleppo-based activist Mohammad Wissam said the army has taken advantage of the fact that rebels have recently turned their sights against Islamist fighters.
"The army has deployed en masse around the east of the city, and families residing in the area have started to flee for other safer neighbourhoods and villages" fearing an all-out assault, he said.
Aleppo has been devastated by fighting between government and rebel forces that began in mid-2012.
Control of the city is now divided between the regime and rebels, and the opposition also holds much of Aleppo province.
In other violence a Saudi suicide bomber and fighter from the Al-Nusra Front Islamist group blew himself up at an army checkpoint late Monday, killing 13 soldiers and pro-regime militiamen, the Observatory said.