Syrian government forces bombarded a central neighbourhood of Aleppo on Sunday after a day of fierce clashes with rebels who tried to take the regime-controlled district, a watchdog said.

Several houses were destroyed in the shelling of the northern city's Midan district, which is under regime control, said the Syrian Observatory for Human Rights.

Fierce battles broke out on the edge of Midan on Saturday, after rebels tried to take over the district from their stronghold in Bustan al-Basha.

A main water pipe in Bustan al-Basha was destroyed, either by air strikes or the fighting, and water shortages were reported by residents in Aleppo.

In the eastern city of Deir Ezzor, the army shelled the neighbourhood of Jubaila, while two people were killed at a checkpoint in Hamdaniyeh district and a third was shot dead by a sniper in Jura.

Shelling attacks were also reported in the northwestern province of Idlib and in the southern province of Daraa, but there were no reports of casualties thus far, the Observatory said.

The violence followed a bloody day in which 135 people -- 63 civilians, 33 rebels and 39 soldiers -- were killed nationwide, the Britain-based Observatory reported.

As many as 38 people were killed by shelling attacks on the districts of Shaar, Halwani and Sid al-Luz on Saturday, the watchdog said. The names of 17 have been documented thus far.

Another 17 bodies were discovered in a trench in Aleppo city, while at least 11 people were killed in shelling in Tadamun and Yarmuk Palestinian camp in Damascus.