Almost 300,000 children in Mosul have been cut off from access to clean water as the battle to retake the city intensifies, UNICEF warned on Wednesday.

A major pipeline was destroyed in a part of the city still controlled by Islamic State, meaning that tens of thousands of families in eastern Mosul are now without safe water.

"Children and their families are facing a horrific situation in Mosul. Not only are they in danger of getting killed or injured in the cross fire, now potentially more than half a million people do not have safe water to drink," said Peter Hawkins, UNICEF Representative in Iraq.

The Iraqi government is bringing in water to try and replace the loss, but the supply will not be enough to meet the needs of all the residents.

Hundreds of thousands of children are therefore at risk of exposure to waterborne diseases such as severe diarrhoea and the threat of malnutrition, UNICEF said.

"Unless running water is restored in the next days, civilians will be forced to resort to unsafe water sources," the organisation said. "Children in affected areas are already strained from years of extremely harsh living conditions."

UNICEF is working with the Iraqi authorities to reactivate nearby water treatment plants to help increase the supply.

"UNICEF urges all parties to the conflict to allow these critical deliveries and repairs. Civilian infrastructure must never be attacked," Hawkins said.