"We condemn in the strongest terms possible disruption of election processes and acts of violence during voter registration... These should be stamped out and those responsible dealt [with] harshly by the law," she said in a statement.
Modise said citizens had the right to exercise their vote in a safe and peaceful environment without intimidation.
Colonel Sabata Mokwabone said on Sunday three women and four men allegedly forced entry into a voter registration station at Itlameng Primary School on Saturday around 07:40.
Damaging election material is prohibited in terms of Section (1) (c) of the Electoral Act of 1998, he said.
The group allegedly arrived at the school and demanded registration material from IEC officials.
They then removed IEC banners from the school fence and set them alight before fleeing the scene, Mokgwabone said.
They were arrested on Sunday afternoon. They are aged between 20 and 33.
Modise called for an investigation as to why the seven people were not immediately arrested at the scene.
NOW THEY WANT TO CHANGE OUR 'CONSTITUTION' TO ENHANCE THEIR TRIBAL DICTATORSHIP POLICIES!