Johannesburg – Four houses in Rosettenville were set alight on Saturday as residents took to the streets to protest against drug-dealing and prostitution, Gauteng police said.Smoke billowed from the homes suspected to belong to drug dealers, with firefighters rushing to the scene to locate the source of fire, said Warrant Officer Kay Makhubele.He said officers fired rubber bullets and stun grenades at the crowd around 13:00 because it was an illegal gathering.An elderly woman fell and injured herself. She was treated by paramedics.Residents later re-gathered.Makhubele said it was hard to estimate the crowd size because they were scattered in large groups.Fed-up residents took to the streets in a similar fashion last week.Last Sunday, they forced their way into homes believed to be used for drug dealing and prostitution, carrying out the furniture and setting it alight.Household goods were carried out of four houses and destroyed between 10:00 and 13:30 before police managed to get the crowd to disperse, Captain Mavela Masondo said at the time.None of the homeowners has laid any criminal charges, but police are investigating incidents of malicious damage to property and public violence.No injuries were reported."People are not supposed to take the law into their own hands. This constitutes a criminal offence," Masondo warned."If you have evidence, come forward and give it to us. And if you don’t get any joy from the police, then it will be escalated to the cluster commander and provincial office."