The accident happened on the Vryburg road between Setlagole and Mahikeng at around 11.30am when a minibus taxi, driving from Taung to Mahikeng, overturned, said spokesman Sam Mokaila in a statement.
Six people died on the scene and a number of critically injured passengers were taken to hospital.
The cause of the accident was being investigated.
Premier Supra Mahumapelo conveyed his condolences to the families of the deceased.
“On behalf of the government and people of Bokoni Bophirima, I wish to convey my heartfelt condolences to the families and friends of the deceased, and wish those injured a speedy recovery,” he said.