More arrests were expected after four rightwing extremists were held for suspected terrorism charges, police said on Monday.
Free State police spokesman Brigadier Billy Jones said his team was investigating further.
“Yes, we are expecting to make more arrests but we cannot reveal further details at the moment, “ he said.
The four were arrested on Sunday.
“The suspects are aged between 40 and 50 year-old,” said Jones.
“Their premises were searched and evidence supporting the investigation was seized.”
Jones said the arrests were the result of a successful joint law enforcement operation.
He said the group would be charged and brought before a court soon.
No further details about the police operation or where the four people were arrested were given.
Meanwhile, the newly established Federal Freedom Party (FFP) said in a statement that at least two of the people arrested are members of their party.
Its national secretary Francois Cloete said their president and a member of their executive council were arrested in Mookgopong (Naboomspruit), Limpopo.
Cloete described FFP as a “party that promotes self-determination of the Afrikaner / Boer people in a confederal political model”. - Sapa