Heavy rains have caused rivers in Zambia, Zimbabwe, Mozambique and Malawi to burst, killing three people in Malawi since Friday and forcing hundreds of others to flee their homes.

Seven people have been killed and tens of thousands displaced in Mozambique in the last two weeks, the national relief agency says. U.N. agencies say three have been killed in Zambia.

In Zimbabwe, state media have reported 27 people have been killed by floods since mid-December but relief officials have not confirmed the figure. Some victims in the region were killed by crocodiles.

In Malawi, floods swept away livestock and inundated agricultural land.

"Crops and livestock have either been destroyed or displaced and people seeking refuge are at risk of drowning as most rivers are swollen," Lowford Palani, the acting commissioner in Malawi's flooded Chikwawa district, told Reuters on Thursday.

Palani said more than 200 people in 24 villages in the southern district, which has experienced food shortages in the past as a result of floods, had been displaced since last week when heavy rains caused the Shire and other rivers to overflow.

The flooding in Malawi came as authorities in a number of neighbouring countries warned that the crisis threatened to devastate their agricultural sectors and destroy roads, bridges and other infrastructure in the region.

Zambian President Levy Mwanawasa launched a fresh appeal for some $13 million in aid from Western donors to help his government cope. It came after flooding cut off a key trade route with Malawi and Mozambique.

"Normally it is not right to appeal for support at occasions of this nature, but I am concerned with the damage being caused to key infrastructure, hence my appeal to donors," Mwanawasa told state-owned television late on Wednesday.

"The government alone cannot manage to respond to the crisis," he said.

FEARS RISE IN ZIMBABWE

Heavy downpours are common in southern Africa during the annual rainy season, which runs generally from November to April, but the relentless rain is unusual and has caught officials off guard.

Concerns are especially high in Zimbabwe, which has struggled to feed itself amid a deep economic slide that has been marked by chronic shortages of food and fuel, rising poverty and inflation over 8,000 percent.

Agricultural production in the once prosperous southern African nation has sharply declined since 2000 when Zimbabwe President Robert Mugabe's government began seizing thousands of white-owned farms and distributing the land to poor blacks.

Mugabe's cash-strapped government, which had pinned its hopes for an economic recovery on a good harvest in 2008, is working with aid agencies to assist villagers who lost houses and crops to the raging floodwaters.

But Zimbabwe's meteorological services department dashed hopes of a break in the weather when it said on Wednesday that "significant rains" and heavy storms in the coming days could worsen the flooding in the northern part of the nation.

Mozambique also is struggling to cope with floods in its central provinces. The United Nations warned earlier this week the floods there could be worse than those in 2000-2001, when 700 people died and another half a million became refugees.