Heavy rains and flash floods have hit 13 of Sudan’s 18 states, affecting more than 288,000 residents and refugees, according to the United Nations.

In neighbouring South Sudan, the deluge affected and displaced about 426,000 people, exacerbating the swelling humanitarian needs in Sudan, the UN said.

In Sudan, thousands of refugees were relocated to different camps, while others took shelter in villages that were spared, but many are now living on the streets.

“They have become homeless,” said Ibrahim Mohamed, a senior official at Sudan’s refugee commission.

“We are facing a serious challenge of finding new land to relocate them to.”

Torrential rains pummel Sudan annually between June and October, often leaving the country grappling with severe flooding that wrecks properties, infrastructure and crops.

Last year, Sudan declared a three-month state of emergency as flooding the UN says was the country’s worst in a century left about 140 people dead and 900,000 affected.

So far this year, the floods have killed more than 80 people nationwide and damaged or destroyed about 35,000 homes, according to Sudanese authorities.

In the al-Jabalain district of Sudan’s White Nile state, neither villagers nor refugees were prepared for the inundation.

“Villagers say they have not witnessed such floods in 40 years,” said Anwar Abushura, the head of al-Qanaa camp.

Many refugees had to make their way through stagnant floodwater to salvage building materials and belongings from the collapsed shelters.

Aid workers have warned of a looming outbreak of diseases among the doubly displaced refugees.

Al-Qanaa camp head Abushura said they were expecting a “medical disaster”.

Some 150 refugees from al-Qanaa and the nearby al-Alagaya camp, including children, were diagnosed with malaria on Monday, according to figures compiled by Sudan’s refugee commission.

At al-Alagaya camp, where many refugees were relocated, South Sudanese refugee Nagwa James pointed to shelters that had buckled under the relentless torrents of water.

Mohamed Ali Abuselib, head of the camp, said refugees had been moved from low-lying areas. but most are in the open and, he added: “We are expecting more floods.”