A trial court on Tuesday found prosecutors had insufficient preliminary evidence against Winnie Mandela, wife of black leader Nelson Mandela, in a case involving the slaying of a 14-year-old boy and adjourned the case until next week.

Police earlier used batons to disperse more than 300 Mandela supporters outside Johannesburg's Rand Supreme Court building, witnesses said, leaving at least one woman injured after officers accused the crowd of blocking traffic. The hearing into the case, which has pared Mrs. Mandela's once mass popularity in black townships but left her with a hard core of support, began Monday.

Judge M.S. Stegmann adjourned the trial of Mrs. Mandela, 56, and three co-defendants until next Monday to give prosecutors time to more firmly link her to charges of kidnapping. The accused will not plead until the charges are settled.

The judge partially accepted defense arguments that the state's case was vague and made pleas impossible. Mrs. Mandela and the others each face four counts of assault and four of kidnapping, which carries a maximum penalty of death.

The court said the prosecution had to show Mrs. Mandela was present at the time of the abduction of the boy, who was later murdered, and that she had knowledge one of her vehicles was used in the abduction. She has denied the charges.

Chief defense counsel George Bizos had said the state was trying to blame Mrs. Mandela for "actions of others" and the kidnapping charges were so imprecise they should be quashed.

Chief prosecutor Jan Swanepoel had noted he intended to submit that all the accused be found guilty on the basis of common purpose, or taking responsibility for the acts of others.

Despite unease in African National Conference circles at Mrs. Mandela's alleged role in the crimes, an official statement has charged the trial is part of "a pattern of harassment and persecution to which Comrade Winnie has been subjected for the last 30 years."