A crazed 32-year-old man deliberately drove a car through a crowd at one of Melbourne’s busiest intersections in an “evil” act that left 19 people injured and raised fresh questions about the adequacy of security measures to protect pedestrians.

In an horrific incident that occurred less than a year after a driver killed six people in a nearby pedestrian mall, a driver aimed his white SUV at a pedestrian crossing outside Flinders Street station, one of the city’s main transport hubs. The incident occurred at 4.41pm during the busy pre-Christmas shopping rush.

Police said the driver, an Australian citizen of Afghan descent, had a history of drug use and mental health problems and was not believed to have been motivated by extremism.

Wearing jeans and a white t-shirt, the man crashed the car into a tram stop before an off-duty sergeant who was passing by rushed to the vehicle, fighting with the man before subduing him. Both men were injured.

Describing the incident, a German tourist staying at the Doubletree by Hilton Hotel, which overlooks the scene, told The Telegraph she “heard people screaming” and observed the chaos through her tenth-floor window.