About 100 people have been killed in fighting in Syria, activists say, most of them in the two main cities, Damascus and Aleppo.
Several Aleppo neighbourhoods have been left without drinking water after a water main was damaged in fighting.
Government forces are reported to have regained control of a barracks on the north-east side of the city, after a lengthy battle with rebels.
The rebels had seized control of the Hanano barracks, one of the largest army posts in the area, on Friday.
During the fighting, a major pipeline supplying water to Aleppo was badly damaged.
The city - the largest in Syria, with a population of about three million - is now suffering from shortages of drinking water, according to the Syrian Observatory for Human Rights, a UK-based opposition activist group.
The BBC reports that video posted by activists from the Shaar quarter of Aleppo shows an apocalyptic scene of destruction in a street devastated by what they said were government air strikes.
The activists said several rebel-held parts of Aleppo were similarly bombarded.
Activists say at least 23,000 people have been in the 18 months since the start of the conflict.
