At a time when Yemen is already mired in escalated fighting, widespread hunger and a major coronavirus outbreak, the spate of torrential rains is exacerbating the world's worst humanitarian disaster.

"The combination of coronavirus, conflict and heavy rains this year is hurting millions of Yemenis across the country," said Abdi Ismail, the head of the International Committee of the Red Cross mission in Yemen.

In southern Yemen, 33,000 displaced people who were sheltering in camps lost their tents and belongings in the floods, the ICRC reported, adding that dozens have died across the country.

In the impoverished western provinces of Hajjah and Hodeida, security officials said 23 people were killed or missing over the last 24 hours and 187 homes were destroyed.

With torrents sweeping away roads and dozens of cars, hundreds of newly displaced families in the area have become stranded without access to food.

Dirty floodwater has contaminated wells that many Yemenis rely on for water.

A hotel marooned in muddied water in the capital, Sanaa, collapsed late on Monday, killing four people and injuring three. Rescue teams are still searching for other missing people.

In the central province of Marib, a refuge for some 750,000 Yemenis who have fled Houthi rebel offensives since the start of the war, days of abnormally intense rains have hit 5500 families, submerging their tents in water and mud and washing away their food aid, Yemen's official SABA news agency reported last week.

The devastating floods in the Arab world's poorest country have exacerbated a cholera outbreak, with 127,900 suspected cases across eight provinces since January, the World Health Organisation said earlier this month.

The ICRC warned the floods have also accelerated the spread of dengue fever and malaria, as mosquitoes carrying the diseases breed in puddles.

Yemen's war, now grinding into its sixth year, has killed over 100,000 people and brought millions to the brink of famine.

Australian Associated Press