South Africa has accused three expelled Rwandan diplomats of links to the murder and attempted murder of Rwandan dissidents living in South Africa.
Justice Minister Jeff Radebe said South Africa had evidence linking them to “illegal activities”.
The diplomats were expelled on Friday following an attack on the home of exiled Rwandan dissident Kayumba Nyamwasa in Johannesburg.
Rwanda denies involvement in such attacks in South Africa.
It retaliated to the expulsions by ordering out six South African diplomats.
Mr Radebe’s spokesman, Mthunzi Mhaga, told international media that investigations “revealed direct links between the expelled diplomats and the criminal networks that relate to the recent attacks on Rwandan officials who are under protection in South Africa”.
Armed men raided the home of Lt Gen Nyamwasa, the Rwandan army’s former chief of staff, last week, but he was not there at the time.
The attackers ransacked the property, and left with a computer and some documents.
Gen Nyamwasa has survived two previous assassination attempts, including a shooting in Johannesburg in 2010 after fleeing Rwanda.
He sought asylum in South Africa after falling out with Rwanda’s President Paul Kagame.
In January this year, the body of a Rwandan former intelligence chief turned dissident, Patrick Karegeya, was found strangled at a hotel in Johannesburg. He had apparently been murdered.