Syrian children fill plastic containers with drinking water in Aleppo city, Syria, on Aug. 4, 2015. (Xinhua/Abd Fayad)

GENEVA, Aug. 9 (Xinhua) -- The UN Children's Fund (UNICEF) warned Tuesday that two million people living in Syria's Aleppo city have been cut off from water supplies following attacks on the electricity transmission station that pumped water to the eastern and western parts of the war-torn city.

"Children and families in Aleppo are facing a catastrophic situation. These cuts are coming amid a heat wave, putting children at a grave risk of waterborne diseases," said UNICEF's representative in Syria, Hanaa Singer, in a statement.

"Getting clean water running again cannot wait for the fighting to stop. Children's lives are in serious danger," she added.

Though authorities managed to put in place a power line on Aug.4, the alternative network was damaged by fighting less than a day after water supplies were restored, UNICEF explained.

UNICEF stressed that urgent repairs to water-pumping facilities are needed since this is the only way to restore critical supplies to the two million people living in the city.

If this is not done, residents will have no choice but to resort to risky practises, such as drinking water from wells which may be contaminated by faecal matter rendering it unsafe to drink, UNICEF reported.

"We urge parties to the conflict to immediately allow safe access for technicians to conduct critical repairs to the electricity and water systems," said Singer.

"Civilian infrastructure like electricity and water pumping stations must never be attacked," she reminded.