Mozambique dam near overflowing

At least 15,000 people remain in immediate danger

A huge dam currently holding back thousands of cubic metres of flood water in Mozambique is close to overflowing and may have to be opened.

Silvano Langa, director of the National Disaster Management Institute, told the BBC that the Cahora Bassa dam - the country's largest - was virtually full as it has been receiving increased discharges of water from neighbouring Zimbabwe and Zambia.

If they open the dam as they may be forced to we could see a major loss of life

Alan Hooker, aid worker

Mr Langa said the authorities had been forced to allow an increased amount of water through to the floodplain of central Mozambique, inundating more areas.

Officials estimate that 15,000 people are in immediate danger and should be evacuated.

And more than 70,000 people, including the 41,000 residents of the town of Marromeu, would have to be evacuated if the dam is opened.

A total of 41 people have been confirmed dead, but aid agencies warn that the number could rise.

More lives could be lost if dam is opened

"If it continues raining as forecast and if they open the dam as they may be forced to, we could see a major loss of life", said Alan Hooker, of the aid group World Vision.

About 77,000 have been left homeless as a result of the floods, the second worst to hit the country in a year.

Up to 50,000 have been made homeless in the neighbouring states of Zambia and Malawi.

South African assistance

South African rescue workers are making their way to the area to estimate how many aircraft will be needed for a mass evacuation.

South African President Thabo Mbeki is reportedly poised to commit the South African Defence Force to respond to Mozambique's request for international help.

During devastating floods in Mozambique a year ago that killed 700 people, South African pilots played a critical role in rescue operations and in providing humanitarian aid to flood victims.

Mr Langa said an operation to evacuate those in danger, mainly in the central districts of Caia and Mutarara, was under way but had been hit by a shortage of air transport.

Mr Langa said just three large helicopters were involved in the operation to airlift the stranded people to temporary shelters on higher ground, as well to distribute relief aid.

While some 200 boats are also involved in the evacuation exercise, the surging currents are making them less efficient.

Rains have washed away roads and bridges in the provinces of Zambezia and Sofala, hampering efforts to distribute aid by road.