The United Nations says nearly two million people are in desperate need of water in the besieged Syrian city of Aleppo.
UNICEF said violent air strikes launched on the city on Friday prevented repairs to a damaged pumping station supplying rebel-held districts of the city.
The agency added that in retaliation, a nearby station pumping water to the rest of Aleppo has been switched off.
Fresh strikes were also reported in the city on Saturday, as the Syrian Army pressed on with its push to retake rebel areas.
The latest offensive was launched after a ceasefire collapsed on Monday.