South African police staged a series of raids Thursday targeting former deputy president Jacob Zuma, whose dismissal in a corruption scandal has rocked the ruling party, the African National Congress.

Investigators from the elite FBI-style Scorpions unit swooped down on Zuma's Johannesburg home early in the day, searching the premises for about four hours and leaving with several boxes, witnesses said.

National Prosecuting Authority spokesman Makhosini Nkosi confirmed what he called "search and seizure" operations that he said took place in four provinces across the country.

"This was part of the ongoing investigation into corruption allegations against former deputy president Jacob Zuma," Nkosi said, declining to confirm specific targets of the operation he said aimed to gather further evidence for the state's case.

Zuma, once seen as the front-runner to succeed President Thabo Mbeki in 2009, was fired in June after the corruption conviction of his former financial adviser Schabir Shaik.

Zuma was later charged with two counts of corruption and faces trial in October. He has denied any wrongdoing and suggested he was the victim of a vendetta by his political foes.

The powerful Congress of South African Trade Unions, an official ally of the ANC in government, this week urged Mbeki to reinstate Zuma as his deputy and stop the trial against him -- a demand the government immediately rejected.

Zuma's firing was widely hailed as proof of Mbeki's determination to set an example for the rest of Africa by fighting official corruption. But it opened splits within the ANC, where Zuma remains party deputy president with a large following among the rank and file.

Local reports said raids were made Thursday on Zuma's rural homestead in KwaZulu-Natal, the Durban home and office of Shaik and two other locations.

The raid in Johannesburg was interrupted when armed members of the VIP security detail assigned to Zuma arrived and ordered investigators to stop their work, witnesses said. After a brief standoff, the police search resumed.

Shaik was found guilty of soliciting bribes for Zuma from a French arms firm in return for protecting it from a probe into a massive arms deal. Shaik was sentenced to 15 years in prison, but remains free on appeal.