Flood waters are rising rapidly in Mozambique, threatening to sweep away thousands of people who have been trapped following the heavy rains.

Large areas north of Gaza province are now being affected by rising waters, and the United Nations World Food Programme (WFP) says the Save River has burst its banks.

Aid workers who flew over the Save River in Manica and Sofala provinces reported seeing thousands of people in trees, on roofs and on narrow strips of land, apparently marooned since Monday. There have also been reports of bodies flowing down the swollen river.

Carol Collins of the British charity Save the Children said: "We need helicopters today. These people are very, very desperate. It must be a nightmare for them.

"The water is moving very, very rapidly. I'm sure some of them were washed away."

Several trucks carrying emergency aid became stuck on Friday in the rising flood waters near the town of Save.

As the crisis escalates, the WFP has said it is running out of money to fund the helicopters which are rescuing people and flying food to those cut off by the flooding. The UN is discussing the possibility of new appeals for international assistance, so that the helicopters can continue rescuing those trapped by the flood waters.

WFP spokeswoman Michele Quintaglie says more flood water is expected in Mozambique in the next few days from Zimbabwe and South Africa.

"We are a long way from being out of this crisis. With more water coming the disaster could spread much wider than what we have at the moment," she added.

The Mozambican Government estimates that 200,000 people have been left homeless so far and at least 150 people have lost their lives in the worst flooding to hit the country in 50 years.

Deaths

The floods have also left a trail of destruction in Botswana, Zimbabwe, and northern parts of South Africa, where several roads and bridges have been washed away, power and phone lines have been knocked out and rescue workers are struggling to reach trapped people.

South African police said 21 people had died in the past four days in the flood-hit northern and Mpumalanga provinces, raising the death toll to 76 over the past three weeks.

In Zimbabwe 29 people are reported dead and a further 12 missing. On Friday night flood waters forced a bus carrying an unknown number of passengers off a bridge and into a raging river. No survivors have been found.

A family of seven also drowned when their hut was swept away in southern Zimbabwe and six tourists were feared dead after attempting to cross the Bubi river bridge near the southern town of Beitbridge.