Police used rubber bullets and teargas against a mob which attacked the Wentworth police station in Durban on Wednesday night after a large meeting at the Austerville community hall to discuss the strike at the Engen oil refinery.
Police spokesperson Vishnu Naidoo said the police had reacted after shots had been fired from the crowd.
Three people were arrested.
Three police vehicles and a private vehicle in the vicinity of the police station were damaged.
Earlier, a spokesperson for the refinery's industrial relations forum and worker representatives said part-time workers at the refinery in Wentworth were not interested in prolonging the current strike, nor did they want more money.
The speaker, Desmond D'Sa, told the meeting that workers wanted to talk to the Engen management directly because it had the power to persuade contractors whom it had appointed to negotiate in good faith.
He said the employees were not making unreasonable demands - they were concerned the take-home pay they were being offered this year was lower than last year.
Mr D'Sa said the workers were concerned that the contractors were not acting in good faith. Proof of this was that a representative of the contractors had cancelled talks scheduled for last Saturday, because the Sharks-Cats rugby match was "more important".
Durban sociologist Fatima Meer said Engen was pretending that it was not the employer and it had worked out a "very clever scheme" in which it could exploit workers to the utmost.
The statements were, in fact, made by the Industrial Relations Forum and worker representatives at the Engen refinery. The error is regretted.