At least 1,500 people have died due to cholera and more than 246,000 new cases of the disease have been reported in conflict-riven Yemen in just the past two months, the World Health Organisation (WHO) has said.

The death toll has risen from the 1,300 announced last month, when the number of suspected cases was around 200,000, and there are now 5,000 new diagnoses a day.

The new figures show the disease has increased tenfold in the last two months, Nevio Zagaria, WHO’s representative in Yemen, said at a news conference over the weekend, and now affects 21 of the country’s 22 provinces.

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The first outbreak of cholera was confirmed in October 2016, but by May new cases were being diagnosed at a rate three times higher than the initial estimates. Aid organisations warned last month that the epidemic was spreading, with almost one person an hour dying from the water-borne infection.

Cholera – an acute diarrhoeal infection caused by ingestion of contaminated food or water – can kill the young, elderly and otherwise sick in hours if vital fluids are not replaced.

A quarter of the dead so far are children, the UN health agency said.

The situation in Yemen Show all 14 1 /14 The situation in Yemen The situation in Yemen Houthi supporters trample on a US flag during a gathering mobilizing more fighters into several Yemeni battlefronts, in Sana'a, Yemen EPA The situation in Yemen People carry the coffins of men, who were killed in the recent Saudi-led airstrikes during their funeral, in the Old City of Sanaa, Yemen AP The situation in Yemen Pro-government fighters give food to Yemeni children on the road leading to the southwestern port city of Mokha. Yemeni rebels are putting up fierce resistance in a key Red Sea port city where they are encircled by pro-government force Getty Images The situation in Yemen A Yemeni stands in front of a graffiti protesting US military operations in war-affected Yemen, in Sana'a, Yemen. According to reports, US Special Forces troops allegedly disembarked from US helicopters in the Yemeni town of Yakla and attacked several houses belonging to members of the terrorist group Al-Qaeda, killing three high-ranking Al-Qaeda members and nine civilians, six women and three children. One American serviceman has been killed and three injured in the attack EPA The situation in Yemen US Special Forces troops allegedly disembarked from US helicopters in the Yemeni town of Yakla and attacked several houses belonging to members of the terrorist group Al-Qaeda, killing three high-ranking Al-Qaeda members and nine civilians, six women and three children. One American serviceman has been killed and three injured in the attack EPA The situation in Yemen A Yemeni female fighter supporting the Shiite Huthi rebels, and carrying weapons used for ceremonial purposes, takes part in an anti-Saudi rally in the capital Sanaa Getty Images The situation in Yemen Yemeni female fighters supporting the Shiite Huthi rebels, and carrying weapons used for ceremonial purposes, take part in an anti-Saudi rally in the capital Sanaa Getty Images The situation in Yemen A boy shouts slogans next to pro-Houthi fighters, who have been injured during recent fighting, during a rally held to honour those injured or maimed while fighting in Houthi ranks in Sanaa, Yemen Reuters The situation in Yemen Balls of fire and smoke rise from a Houthi-held military camp following alleged Saudi-led airstrikes, in Sana'a, Yemen EPA The situation in Yemen Yemenis search under the rubble of damaged houses following reported Saudi-led coalition air strikes on the outskirts of the Yemeni capital Sanaa Getty Images The situation in Yemen A Yemeni boy looks on as Yemenis search under the rubble of damaged houses following reported Saudi-led coalition air strikes on the outskirts of the Yemeni capital Sanaa Getty The situation in Yemen A Yemeni boy sits amidst the rubble of damaged houses following reported Saudi-led coalition air strikes on the outskirts of the Yemeni capital Sanaa AFP/Getty The situation in Yemen Marine One with US President Donald Trump flies with a decoy and support helicopters to Dover Air Force Base in Dover, Delaware, for the dignified transfer of Navy Seal Chief Petty Officer William 'Ryan' Owens who was killed in Yemen Getty Images The situation in Yemen US President Donald Trump aboard the Marine One to greet the remains of a US military commando killed during a raid on the al Qaeda militant group in southern Yemen on Sunday, at Dover Air Force Base, Delaware, US Reuters

While easily treatable and preventable with proper sanitation procedures, after more than two years of war the country’s health, water and sanitation systems are on the verge of collapse, making the epidemic very difficult to treat.

Saudi Arabia and its regional partners have used the spectre of Iran to justify an extensive bombing campaign on Yemen’s Shia Houthi rebels at the request of the exiled, internationally recognised Yemeni President Abdrabbuh Mansour Hadi.

The Saudi economic strangulation, blockades on Yemen’s air and sea ports preventing the import of food and medicine and the targeting of vital infrastructure such as roads and bridges – and in some cases civilian buildings such as hospitals – have contributed to the dire situation the country’s 27-million-strong population is now facing.

Less than half of Yemen’s medical centres are still functional. A total of 14.5 million people don’t have regular access to clean water and 7.3 million live on the brink of famine.

The UN estimates $2.1bn (£1.6bn) is needed to stop Yemen completely collapsing into a failed state, but donor governments only pledged half that amount at an aid conference in Geneva in April.