Rising Violence Reflects Tensions as Vote on Apartheid Reform Nears : South Africa: Whites will cast ballots Tuesday on power-sharing negotiations with blacks.

The emotional campaign for next week’s white referendum on President Frederik W. de Klerk’s reforms turned dirty Friday when a bomb exploded at offices of the ruling National Party and right-wing students shouted “traitor” and threw placards at the president.

In the confrontation at the University of Pretoria, De Klerk was struck on the head by a placard thrown by a student and was jostled by charging right-wing protesters who scuffled with the president’s security guards.

No one was injured in the altercation, or in the early morning bomb blast at a National Party office in Nylstroom, a hotbed of right-wing activism. But police say right-wing whites are suspected of setting fire Thursday to a church that sheltered black street orphans, killing eight children.

The incidents reflected growing tension in the country as the 3.2 million whites prepare to cast ballots Tuesday that will determine the future of power-sharing negotiations with the 26-million black majority.

Most political experts, while predicting De Klerk will prevail, say the election has tightened in recent days, with right-wing leaders beginning to make inroads among the country’s white voters, about a third of whom remain undecided. A sharp increase in black violence has contributed to the uncertainty across the country and may have driven some whites into the far-right Conservative Party camp.

Blacks cannot vote in the referendum, but more than 225 have been killed since the referendum campaign began three weeks ago. Of 24 people killed on Friday, 18--mostly women and children--died in fighting between rival black factions in Umlazi, in Natal province. And police imposed a curfew in Sharpeville and Alexandra townships, two other scenes of unrest.

Black leaders say they suspect that much of the violence has been sparked by blacks and whites who oppose negotiations and hope that township bloodshed will increase white fears of a future black-controlled government.

As the campaign draws to a close, De Klerk and his opponents have been drawing large, vociferous audiences across the country. The president faces his biggest challenge this weekend when he takes his campaign to conservative, rural Transvaal province.

Although incidents of campaign violence have been rare, a tear-gas canister thrown into a government rally in Bloemfontein on Tuesday injured Hendrick J. (Kobie) Coetsee, the government’s minister of justice. It also forced De Klerk to cancel his speech there. Coetsee was treated for bruised ribs at a local hospital.

At Pretoria’s main university, De Klerk told about 700 students, most of them supporters of the government’s reform program, that the scuffles showed “the ugly face of radicalism.”

De Klerk’s campaign has centered on his contention that a “no” vote would throw the country into chaos, inviting renewed international sport and economic sanctions, and probably result in an uncontrollable black uprising. A vote against his reforms, he said Friday, “will be telling them (blacks) that we agreed on power-sharing but we are now breaking our word. We will be telling them to go away, that we don’t want them. Do you think those 26 million people will just say, ‘Yes, Baas?’ ” The remark earned De Klerk loud cheers and applause.

Nelson Mandela, the African National Congress president, vowed Friday that blacks would “fight back” if the Conservative Party comes to power and attempts to carve out a white-ruled territory for itself. He added that “blacks know that if a Conservative Party government comes to power, civil war is unavoidable.”

De Klerk has promised to resign if he loses the referendum, which amounts to a test of white support for the steps he already has taken to negotiate a new constitution with the black majority. If whites vote “no,” De Klerk would call a new election for the white chamber of Parliament, and analysts say he would probably lose that election to the Conservatives.

Although De Klerk still is favored to win the referendum, his opponents have made some headway with their campaign slogan, “Vote No for a Second Chance.” The slogan appeals to the thousands of white voters who do not support the Conservative Party but worry that De Klerk is moving too fast on the path of reform.

The Conservatives also have tried to frighten whites into voting “no” by suggesting that De Klerk’s reforms will lead inevitably to a government run by the ANC and its allies in the South African Communist Party. The “no” forces, though, have been damaged by the increase in right-wing violence. But many whites remain uneasy with the Conservatives’ close alliance with the militant, neo-Nazi Afrikaner Resistance Movement.

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