Dirty water kills thousands more children living in war zones than bombs or bullets, with children under 15 roughly three times more likely to die due to diarrhoeal diseases than direct violence.
According to a UNICEF report, a total of 86,00 children died from diarrhoea-related illnesses in 16 countries facing protracted conflict, compared to nearly 31,000 who died from violence.
But it is the youngest children who are most vulnerable to crumbling sanitation infrastructure and water scarcity.
Diarrhoeal diseases killed 72,000 children under five in war zones between 2014 and 2016 - a figure 20 times higher than the 3,400 deaths from violence.
“Humans can run away and take shelter from bullets and bombs,” Omar El Hattab, UNICEF regional chief of water, sanitation and hygiene in the Middle East and North Africa, told The Telegraph.
“But when we are deprived of water, we end up withering away or drinking sewage, we will drink any kind of water. Access to clean water is a matter of life and death.”
The report, Water Under Fire, was published on Friday to coincide with World Water Day. It compared World Health Organization mortality data on “collective violence” and “diarrhoeal disease” from 2014 to 2016 in 16 countries beset by protracted conflict - including Afghanistan, Syria, Sudan and Yemen.
In 14 of the countries studied, unsafe drinking water killed thousands more children than the fighting itself - the exceptions being Libya and Syria, which have suffered intense fighting in drawn-out conflicts.
“Water and sanitation services save lives, they should never be interrupted,” Mr El Hattab said. “In many conflicts, these services are often deliberately and indiscriminately attacked. This breaks international humanitarian law under the Geneva Convention and has to stop.
"It’s about time that the international community started respecting the laws that we agreed and ratified a long time ago," he added.
Children are particularly vulnerable to unclean water and dehydration, with diarrhoeal disease the second leading killer of children under five globally. But this is exacerbated in war zones, where infrastructure is crippled and water contaminated.
“It isn’t surprising,” said Tomas Jensen, advisor for tropical medicine at the international medical charity Médecins Sans Frontières.
“[Children] are often the ones at greatest risk, especially young children who haven’t built up immunity to bacteria that can cause diarrhoeal disease."
For instance in Yemen, which has had one of the worst cholera epidemics in recent history, a third of the cases were children under age 5.
The report added that access to adequate water and sanitation adversely affects girls more than boys, making them vulnerable to sexual violence as they collect water or use latrines.
It called for an end to attacks on water and sanitation infrastructure and extra resources for aid agencies and governments to tackle inadequate water supplies.
“The odds are already stacked against children living through prolonged conflicts – with many unable to reach a safe water source,” said Henrietta Fore, executive director of UNICEF.
“Deliberate attacks on water and sanitation are attacks on vulnerable children.”
