JOHANNESBURG, South Africa (AP) _ Fearing a repeat of street warfare that killed dozens of people last month, police on Friday banned Zulu nationalist marches planned for Johannesburg next week.

The Inkatha Freedom Party Youth Brigade told people to stay away from work all week in Johannesburg - the nation's largest city and business capital - and said it planned with marches and protests Monday through Thursday.

''We are going to march,'' said Charles Loliwe, chairman of the youth brigade. ''If anything happens to us, we warn the government it could lead to a Bosnia situation in Johannesburg.''

He spoke before police announced the ban.

A Zulu nationalist march in Johannesburg on March 25 resulted in gunbattles and street clashes that killed more than 50 people in the city and surrounding black townships. Eight of the deaths occurred outside the headquarters of the rival African National Congress when ANC guards opened fire on Zulu marchers.

Loliwe said the marches next week would be in honor of people killed in the March 25 clashes. He said Inkatha would try to prevent people from going to their jobs in Johannesburg.

''Anyone who comes to town will do so at their own risk,'' he said.

Within hours of the Inkatha announcement, police banned all political marches under unrest regulations imposed after the deaths in Johannesburg.

Police Lt. Gen. Koos Calitz said the ban was ''necessary for the combatting or prevention of public disturbance, disorder, riot or public violence.''

The banning order cited weekend marches in the area planned by local groups and the ANC, as well as the Inkatha marches on Monday and Tuesday.

Fighting between supporters of Inkatha and the ANC has killed thousands of people in recent years and threatens to disrupt voting in some areas in South Africa's first all-race election on April 26-28.

The Zulu nationalist Inkatha opposes the vote, likely to be won by the ANC. Inkatha wants autonomy for the traditional Zulu homeland in Natal Province, while the ANC opposes any territories based on race or tribe.

Despite months of negotiations, the dispute remains unsolved and Inkatha is boycotting the election.