Protesters in Bronkhorstspruit, east of Pretoria, set alight several buildings, including a clinic, on Wednesday, according to the South African Police Service.
"A clinic, house and a hall were burnt down in Rethabiseng," said spokesperson Johannes Japhta.
He said the protests had spread to nearby townships.
Seven buildings had been set alight as a result of the protests in the area. Two people were arrested in Rethabiseng on Wednesday and would be charged with public violence and illegal public gathering.
The police arrested more than 50 people after disgruntled Bronkhorstspruit residents set alight a library and a house at around 3am on Tuesday.
No one was injured and the three people who were in the house at the time escaped when the fire started.
Japhta said it was not known if the home owner worked for the Tshwane municipality, but he had previously been a community policing forum member.
The library was completely destroyed, he said. The police opened a case of arson. Japhta said it was not yet known if a petrol bomb had been used.
Violent service delivery protests erupted in the area last week. Protesters torched the Zithobeni satellite police station and municipal offices.
The City of Tshwane said on Tuesday that residents of Bronkhorstspruit, Rethabiseng and Zithobeni in Region Seven had been protesting because they were unable to buy pre-paid electricity.
Spokesperson Blessing Manale said that before Region Seven merged with the city, it used a prepaid electricity system called the Conolog and the system crashed on Monday last week.
"The city has, since the system crashed, called in technicians for repairs, but has been advised that the system was irreparable," he said.
"The region has now intensified its roll-out of the migration programme to transfer residents from the old Conolog system to the Supreme system and calls upon all residents from Bronkhorstspruit, Zithobeni and Rethabiseng to come and register for the new system."
He said the city condemned the vandalism and destruction of property and called for calm in the area. – Sapa