A least 20 people, including pupils, were arrested in Maokeng, Kroonstad during a protest against lack of power in the town on Wednesday, Free State police said.
Spokesman Maseleka Langa said the group was arrested during the morning on charges of public violence and malicious damage to property.
“They threw stones at police vehicles, amongst others.”
Fifteen people were arrested for public violence and six for malicious damage to property.
School children make up about half the number of people arrested.
The town and surroundings areas have been without power for several days.
The Moqhaka local municipality said the long lasting power failure follows an attempt to steal a power cable resulting in an explosion and damages at a power station in town over the weekend.
Earlier, municipality’s technical manager Mike Lelaka said replacements parts were received from Cape Town and had been installed.
It was expected that the electricity supply would be restored by midnight on Tuesday.
Residents had been blocking roads and streets with stones and burning tyres in Maokeng since Monday.
On Wednesday, children joined protesters on their way to school in the protest, while some schools were disrupted by protesters in an effort to force school pupils to join the action.
Classes were interrupted at the Bodibeng Secondary School after protesters pulled pupils from the school.
“Nobody was hurt in the process, but it was total chaos. We had to release the pupils before things got out of hand,” said a school teacher who did not want to be named.
Police were monitoring the situation.