Warrant Officer Kay Makhubela said 15 were set alight and seven damaged on Wednesday night. No arrests were made but investigations were underway.
“It is suspected that residents from the nearby Nancefield hostel did this overnight. They say they don’t have electricity,” Makhubela said.
A large crowd gathered near the depot on Thursday morning demanding Eskom provide electricity in the area.
“The crowd is quite big and so far the protest is peaceful,” he said.
Earlier in the morning, protesters blocked the Sofasonke and Klipspruit Valley intersection with rocks and tyres, disrupting traffic.
Makhubela said the roads had since been cleared but police were monitoring the situation.