Among the dead is a family of four killed in a fire started by lightning, while thousands have been left homeless, officials say.

The storm comes two weeks after the region declared a drought disaster.

The BBC's Mo Allie in Cape Town reports that before the storm, there had been several interfaith meetings to pray for rain.

Our correspondent adds that the storm was anticipated and warnings have been made by the local authorities for the last week.

Local media have dubbed it "the mother of all storms".

Schools and universities have had to shut, roofs were blown off and shelters have been opened for those left destitute.

Residents of the city's many shanty towns have been worst hit as their fragile homes have been unable to resist the strong winds and heavy rain.

Western Cape Disaster Management spokesman James-Brent Styan said that many people had been injured by flying debris.

Cape Town resident Neels Stander told the BBC: "One minute it's a drought, the next it's a storm. No wonder the place is called the Cape of Storms."

President Jacob Zuma has cancelled a trip to Cape Town to open the World News Media Congress because it is not possible to fly there.

BBC weather forecaster Philip Avery warns that Wednesday could bring in excess of 50mm of rain to some western areas of South Africa, accompanied by winds of 60-90km/h.

Coastal areas face the additional hazard of high tides, reinforced by storm waves, some of which may reach 10m.

Thursday should see conditions easing but a passing cold front will introduce much cooler weather in all areas.

In May, the Western Cape province declared a drought disaster after two reservoirs had completely dried up. It was said to have been the region's worst drought in more than a century.

Several other southern African nations were also affected by the two-year drought, which was caused by the El Nino climate phenomenon.

However, many parts of the region are now experiencing bumper maize harvests.