"A house fire broke broke out before nine (am) this morning," Liezl Moodie told AFP, saying three of the dead were minors, including an infant.
Earlier she had told AFP that eight had died, but said one more death had been reported.
"Now there are nine people deceased," she said without details on the ninth death, but saying four remain in hospital with serious injuries.
The cause of the blaze in Mitchells Plein, one of the country's largest townships, was not immediately clear.