The WHO said that on one day last week , 20 cholera deaths and 3,460 suspected cases had been registered in the country, where two-thirds of the population are on the brink of famine.
Cholera has killed 315 people in Yemen in under a month, the World Health Organisation has said, as another aid organisation warned Monday the outbreak could become a "full-blown epidemic".
The WHO has recorded another 29,300 suspected cases of cholera in 19 provinces across the war-torn country from April 27 to Sunday, it said on Twitter late Sunday.
"Cholera continues to spread in Yemen," it said.
The UN health agency said that in a single day last week, 20 cholera deaths and 3,460 suspected cases had been registered in the country, where two-thirds of the population are on the brink of famine.
"The speed of the resurgence of this cholera epidemic is unprecedented," WHO country representative for Yemen Nevio Zagaria told reporters in Geneva by phone from Yemen last week, warning that a quarter of a million people could become sick by the end of the year.
Cholera is a highly contagious bacterial infection spread through contaminated food or water.
Reining in the disease is particularly complicated in Yemen, where two years of devastating war between the Houthis and government forces backed by a Saudi-led Arab military coalition has left more than half the country's medical facilities out of service.
Many health workers in the country have not been paid for seven months.
Zagaria said that humanitarian workers cannot access some parts of the country, and that the number of suspected cholera cases could be far higher than those registered.
At the same time, he said, lacking electricity meant water pumping stations were only functioning in an intermittent way, and the sewer systems were damaged.
"The population is using water sources that are contaminated," he said.
The United Nations is planning to dramatically scale up the number of treatment centres and rehydration centres.
Without dramatic efforts to halt the spread of the disease, "the price that we will pay in terms of life will be extremely high," he warned.
Save the Children on Monday warned that at the current rate more than 65,000 cases of cholera are expected by the end of June.
"Save the Children staff in Yemen are warning that a deadly cholera outbreak could become a full blown-epidemic," it said in a statement.
An epidemic refers to the spread of a disease in excess of normal expectancy, according to the WHO.
"The upsurge comes as the health system, sanitation facilities and civil infrastructure have reached breaking point because of the ongoing war" in Yemen, Save the Children said.
It said the cholera response is "massively underfunded", calling for "urgent financial support".