At least 150,000 people have been displaced in Mozambique due to intense flooding, according to the United Nations.
The UN said on Tuesday that the number displaced is expected to rise as fresh rains spread flooding northward.
At least 40 people have been killed so far by heavy rains and overflowing rivers in the southeastern African country, which is experiencing its worst floods in more than a decade.
"People in high-risk areas are still being rescued," Rita Almeida, a spokeswoman for Mozambique's National Disaster Management Institute, said.
"We are asking people to move out of houses that could be destroyed by rain," Almeida said.
The south of the country has been worst-hit by the flood surge, especially in the province of Gaza where 150,000 residents have been forced to flee to higher ground, Patricia Nakell, a UN spokesperson, said.
Refuge on rooftops
The town of Chokwe, which had been badly damaged in floods 13 years ago, was once again devastated and residents sought refuge on rooftops.
The UN is coordinating relief efforts with non-governmental organisations. Aid agencies and government emergency services have set up temporary camps in elevated areas to aid the flood victims.
"The main needs are tents and clean water, but they basically need everything," said Katherine Mueller, a spokeswoman for the International Federation of Red Cross and Red Crescent Societies.
"There will be a huge need of sanitation, mosquito nets, shelter, kitchen sets and blankets as families begin returning home in the coming weeks."
Water levels on the Limpopo river are reportedly at higher levels than those recorded during the deadly floods in 2000.
The deluge is expected to swell the Zambezi river basin, spreading the disaster to northern and central Mozambique.