Syrian government forces advanced on Sunday south of Aleppo city, a military source and state media said, as they pushed to once again encircle rebel neighbourhoods and reimpose a siege.
"The Syrian army, supported by allied forces, has total control of the armaments academy and expanded the territory it controls in the military academies zone," state news agency SANA said.
An AFP correspondent in the rebel-held east of Aleppo city reported heavy aerial bombardment on the combat zone in the south of the city, where three military schools are located.
Government forces have already recaptured the air force academy and rebels "are now besieged in the artillery academy," a military source said.
If they recapture the school, government forces could then "easily take Ramussa, a suburb south of Aleppo, and reimpose a siege of the rebel districts," said Rami Abdel Rahman, director of the Syrian Observatory for Human Rights monitor.
Once Syria's economic powerhouse, Aleppo city has been ravaged by the war that began with protests against President Bashar al-Assad in March 2011.
It has been roughly divided between regime control in the west and rebel control in the east since mid-2012.
In mid-July, advancing regime forces encircled the rebel-held east, placing the opposition districts under a siege that provoked international concern.
But on August 6, opposition forces seized Ramussa and reopened a route into the rebel-held portions of the city.