Five straight days of rain have killed more than 70 people in southern Africa, and left thousands of people stranded or homeless.

Among the areas worst hit are the densely populated shanty towns and squatter camps around Johannesburg.

Dwellers' homes in the Alexandra township on the edge of the city have been washed away, as streets turn into raging torrents.

The emergency services have been working round the clock to help stranded people to safety.

But floodwaters are continuing to rise.

Johannesburg's main dam is barely coping, and people living nearby are being evacuated in case they too should fall prey to the deluge.

Many of South Africa's roads are impassable, making the task facing rescuers all the more difficult.