Police spokeswoman Col. Noxolo Kweza said rescuers recovered one corpse and were trying to bring three others to the surface Thursday. Kweza said police could not yet confirm the four had been shot and were investigating reports in The Sowetan newspaper that they were shot Monday by guards.

The mine east of Johannesburg is owned by Zuma's nephew Khulubuse Zuma and Mandela's grandson Zondwa Mandela. The two are embroiled in a pay dispute with mineworkers they inherited from several mines they bought from an insolvent company.

In its Thursday editions, The Sowetan quoted one man, 25-year-old Sam Sithole, as saying he went down a shaft Monday with a group of miners that included two of his brothers and encountered three guards.

He said he heard one of the three giving an order to "shoot everyone." "People started running all over when the first men fell," Sithole told The Sowetan. "I jumped over the body of one of my brothers as I fled." He said he later pretended to be dead.

"The killers left me only because they thought I was dead," he said.

The Sowetan reported the toll could be much higher, but that its reporters found only four bodies.

Thulani Seshile Ngubane, an official of Aurora Empowerment Systems, the company that owns the mine, said miners died but the circumstances and the number killed had not yet been determined.

He said none of the dead were Aurora employees, adding that the company stopped mining at the site after a strike in March.

The dead are "illegal miners," he said.

South Africa's National Union of Mineworkers called for an investigation and said "anyone guilty of unprovoked shooting should be charged, tried and punished." The governing African National Congress also called for an investigation.