Anti-apartheid leader Nelson Mandela warned Friday that blacks would turn South Africa "upside down" with protest and turmoil if world sanctions are eased before apartheid is abolished.

"You can expect that mass action in this country is going to be the order of the day," said Mandela, deputy president of the African National Congress, if the 12-member European Community carries out its suggestion to end sanctions as a reward for President Frederik de Klerk's intentions to scrap South Africa's last race laws."If the EC wants this country to be turned upside down" then all it has to do is repeal the sanctions imposed in 1986 to protest segregation, he said.

De Klerk said last Friday that Parliament this year will abolish the last of the country's race laws, including those that classify people by race from birth and stipulate where blacks can and cannot live, and other vestiges of rigid segregation.

Mandela made his comments at a news conference commemorating the first anniversary of his release from 27 years in prison.

Mandela said he remains "very optimistic" about the future of South Africa and reiterated that the ANC, the country's leading anti-apartheid group, is prepared to compromise in talks with Pretoria and to address whites' "genuine fears" of black domination.

But he said the movement rejects any relaxation of sanctions until the race laws are actually repealed and power is shared by people of all races.