There was fierce fighting between insurgents and Syrian government and allied forces along a strategic frontline in southwest Aleppo. In August rebels briefly broke through this government-held strip of land to try to break a siege on rebel-held eastern Aleppo enacted in July.
The Syrian Observatory for Human Rights said there was heavy rebel shelling onto the government-controlled Hamdaniya district, part of this battle front.
Aleppo has been a major battleground in the Syrian conflict, now in its sixth year. Syrian President Bashar al-Assad, backed by the Russian military, Iran's Revolutionary Guards and an array of Shi'ite Muslim militias, wants to take full control of the city.
Russia had declared a unilateral ceasefire from Thursday which was rejected by rebels, lasted three days and did not result in hoped-for medical evacuations from the city or aid deliveries.
The Free Syrian Army (FSA) rebel alliance, which has said it is preparing for a big attack to break the siege of eastern Aleppo, warned residents in and around the city to stay away from Syrian government military buildings for their own safety in a statement on Saturday.
FSA rebel groups said in statements they had repelled various offensives by government and allied forces along the frontline separating rebel- from government-held Aleppo city late on Saturday.