Emergency services are moving thousands of families out of low-lying areas in central and northern Mozambique as rains across Southern Africa swell water levels, official said Friday.

"About 500 families with five members each were evacuated to camps. Six thousand families were affected which makes it about 30,000 people," Belarmino Chivambo, spokesman for the national emergency operations centre, Canoe, said.

Around 2,500 people are housed in temporary settlement camps in the southern province of Gaza as the Limpopo river burst its banks, he said.

"Our main worry is readiness, and to evacuate people so that if the water comes, there will be no loss of life," Chiuvambo added.

He said authorities are concerned about water levels in the Zambezi river basin in the centre of the country, the most vulnerable to flooding as downpours continued, said Chivambo.

Discharges from the Cahora Bassa dam, Mozambique's largest, were increased from 4,900 cubic metres to 6,400 cubic metres per second on Friday following an increase in run-off from the Kariba dam upstream along the Zambia and Zimbabwe border.

Floods have killed nine people in the southern African country this year, according to official figures and almost 20,000 hectares (50,000 acres) of crops have been lost.

Around 4,000 pupils cannot go to school and thousands of people have difficult reaching medical services or shops, Chivambo said.