Millions of people in Yemen are days away from losing clean running water - sparking concerns there could be another spike in the country's cholera epidemic, a charity has warned.
Eight million people will be affected as fuel runs out due to the Saudi-led coalition blockade of the country's northern ports, Oxfam warned.
They will join the almost 16 million people in Yemen who can no longer get clean piped water, leaving more than four in five people without a steady supply of clean water.
Yemen is in the grips of the worst recorded cholera outbreak in historywhich has so far seen almost 950,000 suspected cases since April.
In northern areas of the country petrol stocks are due to run out soon and diesel in approximately eight days.
The country's Ministry of Water reports that seven cities have already run out of fuel and two others will run out soon.
Water supply in places such as the port of Hodeidah is reliant on fuel provided by the United Nations.
Aid agencies agreed to support the water supply networks but they will not be able to continue as fuel is becoming scarce and more expensive.
Oxfam said that urgent action is needed to keep clean water flowing.
Shane Stevenson, Oxfam's Country Director in Yemen said: "The people of Yemen are already being starved to submission - unless the blockade is lifted quickly they will have their clean water taken away too. Taking clean water from millions of people in a country that is already suffering the world's largest cholera outbreak and on the verge of famine would be an act of utmost barbarity.
"The punishment of ordinary civilians is never justified. These are real people whose lives are being callously jeopardized in other countries' war games. Yemen can't take much more, unless the blockade is lifted millions already in crisis will face a fresh catastrophe."
A Saudi-led coalition blockade has closed Yemen's northern ports since 6 November, pushing millions more people to the edge of what is already the world's worst humanitarian catastrophe
.The coalition announced on 23 November they would reopen the ports to aid, but without fuel this will not significantly improve the situation.
Nearly seven million people are at risk of starvation and the UN has warned that unless the blockade is lifted, Yemen will suffer the worst famine of any country in recent years.
The local cleaning department in the city of Taiz and surrounding areas ran out of fuel this week and the clearing of rubbish from the streets has been halted - creating an ideal environment for new diseases such as dysentery and diphtheria to quickly spread.
Stevenson said: "The longer the blockade continues, the more people need our help but the less help we are able to offer. The international community cannot be allowed to turn its backs on the suffering in Yemen. All those with influence over the Saudi-led coalition are complicit in Yemen's suffering unless they do all they can to push them to lift the blockade."