Syrian rebels warn of "collateral damage" and call on civilians in war-torn city to stay away from government positions.
Fighting has intensified in Syria’s divided city of Aleppo, a day after a "humanitarian" pause announced by Russia ended, a monitoring group and rebels said.
Unidentified jets bombarded rebel-held areas in the south-western part of Aleppo on Sunday, the Syrian Observatory for Human Rights said.
Lebanese Al-Manar TV, run by the Syria-aligned armed group Hezbollah, broadcast footage of tanks and fighters advancing under heavy fire along a ridge reportedly in the Aleppo countryside.
Rebels have also confirmed the bombardments on the opposition-held areas of the city.
The activist-run Shahba Press reported that government artillery shelled the strategically important village of Khan Touman, which overlooks the highway connecting Aleppo and government-held cities in the center of the country.
But a commander from the rebel Syrian Free Army, speaking on condition of anonymity, said opposition fighters had repulsed the attack and inflicted "big losses" on the regime forces.
His report could not be independently verified.
Meanwhile, opposition rebels have also launched counter-attacks, shelling the regime-held southern district of al-Hamadaniyah. No casualties have been reported so far.
A leading northern Syrian rebel coalition warned civilians in Aleppo to stay away from government positions around the city, as rebels and pro-government forces clashed along the city’s outskirts.
Yasser al-Yousef, a spokesman for the Nour el-Din al-Zinki rebel faction in Aleppo said an operation to break the government’s siege of the rebel-held eastern districts of Aleppo was "coming."
Yousef said rebels would not target civilians in government-held districts, but warned of collateral damage from the anticipated operations.
On Thursday, Russia, a key military ally of Syria, had announced an 11-hour ceasefire to allow civilians, rebel fighters and injured people to leave opposition-controlled eastern Aleppo, promising them safe passage.
It later extended the ceasefire for another two days. Rebels, however, rejected the offer.
The Syrian opposition said there were no guarantees that wounded evacuees would not be arrested by government forces and no provision for supplying humanitarian aid to those remaining in the enclave.
The fighting between Syrian government forces and rebels ran in parallel with renewed clashes further away from the city between Turkish-backed opposition forces and Syrian Kurdish forces, over territory formerly held by the Islamic State of Iraq and the Levant (ISIL) group.
The activist-run Aleppo Media Center said Turkish forces struck over 50 Kurdish positions on Sunday alone.
The US has backed both the Turkish-backed forces and the Syrian Kurdish forces in the area, though it has clarified that it does not support the Syrian Kurdish forces that have come under Turkish attack in the Aleppo countryside.
The Turkish military intervened in the Syrian war in August this year under orders from Ankara to clear the border area of Islamic State fighters and U.S.-backed Syrian Kurdish forces linked to Turkey’s own outlawed Kurdish insurgency. The Turkish government considers both to be terrorist groups.
Some 250,000 to 300,000 civilians are thought to be trapped in eastern Aleppo, with dwindling food supplies and extremely limited medical care in underground hospitals that have been hit repeatedly by air strikes.