“The regime forces advanced into Al-Malaab Street (in Salaheddin district) with tanks and armoured vehicles and fierce fighting is now taking place in the area,” Wassel Ayub, a commander in the rebel army, told the news agency.
The foray came after the army shelled several districts of the northwestern city before dawn, killing 12 people, while another civilian died elsewhere in the province, according to the Syrian Observatory for Human Rights.
Among the dead were a woman and her two children, killed when a shell landed on their house in Al-Mashatiyah neighbourhood, the Observatory said.
The neighbourhoods of Qatarji, Tariq al-Bab and Shaar also came under heavy shelling, the Britain-based watchdog said.
The Syrian Revolution General Council, a network of activists on the ground, reported overnight shelling in the neighbourhoods of Al-Kalassa, Shaar, Sukari and Tariq al-Bab as well as heavy artillery fire aimed at the Bustan al-Qasr and Fardoss districts.
The violence came as rights group Amnesty International expressed concern about the plight of the city’s civilians, citing satellite images indicating an apparent increased use of heavy weapons in the area.
Amnesty warned forces loyal to President Bashar al-Assad, who has been trying to crush an uprising against his rule that broke out in March 2011, and rebels opposing him, that attacks on civilians would not go unpunished.
“Amnesty International is sending a clear message to both sides in the fighting: Any attacks against civilians will be clearly documented so that those responsible can be held accountable,” Amnesty’s Christoph Koettl said in a statement.