Water availability in Syria has been halved since the conflict there began nearly four and a half years ago, and millions of people around the country endure “long and sometimes deliberate interruptions to their water supplies,” the United Nations said Tuesday.

In a report about the scarcity of water in Syria, Unicef said it had recorded 18 deliberate cuts to the public water supply in the northern city of Aleppo this year. “Taps in some communities were left dry for up to 17 days in a row — and for over a month in some areas of the city,” the report asserted, accusing antagonists in the conflict of “using water to achieve military and political gains.”

Unicef estimated that 2.3 million people in Aleppo, 2.5 million in Damascus and 250,000 in the southern city of Dara’a are suffering water shortages, and that children sent by families to fetch water from collection points often encounter lethal dangers from fighting. At least three children in the Aleppo area have been killed in recent weeks while collecting water, the report said.