On Tuesday the service announced that it had only one day's supply of blood left, mainly due to a high number of traffic accident victims in the past weeks. It said 6,000 litres of blood were needed urgently.

More than 600 South Africans have been killed on the country's roads this month and thousands more have been injured.

The Blood Transfusion Service says people have been arriving to donate blood at mobile clinics and at stands in shopping centres.

More accidents expected

Despite the good response, the service is still urging donors to continue to come forward, as drunken driving over the New Year is expected to bring another spate of serious road accidents.

The problem has been aggravated by the fact that many regular donors have gone home to rural areas or to the coast for the holiday season.

Road accidents: Thousands injured over Christmas

Last year by the time the season was over more than 1,000 South Africans had lost their lives, and 6,000 others had been injured.

This year the government has been running a special "arrive-alive" campaign, to highlight the lethal combination of speed and alcohol.

Extra police officers with breathalysers and radar speed detectors have also been deployed.