Police arrested three white men Wednesday and seized a cache of automatic weapons in connection with a recent attack on a bus in which six blacks were killed and 27 wounded.

The three men are believed to be linked to extreme right-wing white groups opposed to government plans to end apartheid, according to local journalists. Police declined to comment on the three men's political affiliations.Police said the men were arrested in a raid in Durban, and AK-47 assault rifles and other weapons were seized. Police Col. R. Reynolds said the men would appear in court but gave no other details.

A bus used by blacks was attacked with automatic gunfire near Durban on Oct. 9. Everyone on the bus was either killed or wounded.

If the suspects do have right-wing affiliations, the attack would be one of the worst racial incidents since white extremists vowed to fight government plans to scrap apartheid and share power with the black majority.

In other developments, the pro-apartheid Conservative Party threatened a tax revolt by at least 1 million whites to force the government to call elections and block plans to share power with the black majority.

A proposal calling on whites to refuse to pay taxes was presented late Tuesday to loud cheers at the Conservative national conference in Durban. Party leaders said they would study the proposed tax revolt as part of a comprehensive "resistance" strategy.

The party demanded that President F.W. de Klerk agree to whites-only elections on plans to end white-minority rule.