Four workers at the Harmony goldmine in Kusasalethu, west of Johannesburg, were targeted on Saturday night.
A home and a car were set alight in in the nearby Wedela township, along with another home and car at the Deelkraal residence owned by the mine.
NUM regional secretary Mbuyiseli Hibana said the attacks had followed the sacking of Amcu members for intimidating miners into staying away from work on Thursday and Friday.
“We want the company to take action against these thugs who have decided to target our members,” he said. “This intimidation … has been happening for some time now and our members … cannot tolerate it anymore.”
On Friday, NUM youth structure national secretary Bonginkosi Mrasi’s home was burnt down in nearby Orange Farm.
Last week, five miners were killed in a collapse at the Harmony mine, which is owned by Patrice Motsepe, brother-in-law of Vice-President and ANC leadership contender Cyril Ramaphosa.