Prime Minister Robert Mugabe today launched his sharpest attack on the South African government, blaming it for last week's bombing of his party headquarters.

Speaking tersely at a press conference, he also threatened to isolate in reeducation camps "elements" working against his government in the party of white former prime minister Ian Smith, unless they repent or leave the country.

The tough remarks are bound to set off reverberations in Zimbabwe's 180,000 white-minority population. White emigration is already running at a record of about 1,800 a month.

For several months Mugabe has criticized whites who failed to accept his policy of reconcilation after the country's independence war but his threats were more specific today. In addition, he promised to introduce "practical" measures to deal with dissidents early in the new year.

Aside from the bombing, which killed seven persons, he accused South Africa of recruiting mercenaries for coups, a reference to last month's abortive attempt to replace the government in the Seychelles Islands; destabilizing the economies of its neighbors and invading territory "without any shame and . . . with impunity."

Saying he would announce his plans "very soon," he added: "I want people to enjoy their Christmas and New Year's. Let's not cause them indigestion by publishing news they cannot digest."

Nine whites, including a member of Parliament, have been arrested under emergency laws in recent weeks for antigovernment activities but no charges have been brought.

Mugabe also accused members of the party of black ex-prime minister Abel Muzorewa of working against the government, as well as those in Smith's party.

"There are agents within these parties who continue to lend themselves to manipulation for South Africa and for its own purposes," he said. "For filthy lucre, they are prepared to throw bombs and plant explosive devices."

"Those who cannot accept" the government's policy of reconciliation between the races "have no place in Zimbabwe," he said. "They cannot be allowed to continue to harm our endeavors."

He called upon them to repent or leave the country.

"Certainly they can have a place in Zimbabwe," he said, provided "they are isolated from the rest of the people for reeducation and discipline."

He said his policy of reconciliation, which has won him acclaim in the Western world, will continue but added: "The very people we forgave are the ones who are taking advantage of our spirit of amity to destabilize the situation and even to overthrow my government."

Mugabe made the remarks on returning from a five-day visit to Mozambique, which harbored his guerrillas during the revolution.

Earlier this week in Maputo he said his government "is bound to mete out harsh punishment to this clan of unrepentant and criminal savages."