Twenty-eight female guards were unfairly dismissed by a security company because the client‚ Metrora.
Warrant Officer Kay Makhubela said they held a joint operation at 5am at a hotspot where metal theft, rape, and the dismantling of stolen cars was apparently taking place.
He said the horses, which were in "very bad condition", had been used by thieves to pull carts containing stolen metal and car parts. They were in the care of the SPCA.
Everything else on the site had been removed and the shelters there had been destroyed.
"The people present ran away when they saw police approaching," said Makhubela.
No arrests had been made and police were investigating, he said.