A man deliberately drove into pedestrians, killing four people and injuring more than 20, in the centre of Australia's second largest city of Melbourne, but police said the incident was not terrorism-related.
Police eventually rammed the car and shot the 26-year-old driver in the arm, before dragging him from the vehicle and arresting him.
Police said the man had a history of family violence and was wanted over a stabbing earlier in the day.
Pursued by police cars, the man had been seen driving erratically before speeding into a pedestrian mall, ploughing into people, police said.
CCTV showed several people diving into a shop as the car raced along the footpath.
One of the dead was a child.
Four children, including a three-month-old baby, were taken to Melbourne's Royal Children's Hospital, said a hospital spokesman.
"We're not regarding this as a terrorism-related incident," Victoria state police commissioner Graham Ashton told reporters.
Police had earlier chased the driver, who was wanted over a domestic assault and driving offences, Mr Ashton said.
Video from a witness showed a maroon coloured car driving around in circles in an intersection outside Flinders St railway station in the city's central business district, with the driver shouting at people and hanging his arm out the window.
Two people approached the car, apparently trying to stop it before it drove off with police chasing.
Witness Maria Kitjapanon told Melbourne's Age newspaper that police eventually rammed the car.
"There were probably ten police surrounding that guy's car, with guns drawn, and they fired into the car. Then they dragged someone out via the passengers side, then all ten of them sat on top of him," she said.
Melbourne is hosting the Australian Open tennis grand slam and is packed with thousands of tourists, only a few blocks from where the incident occurred. Police said the tennis tournament continued as normal.
Australia has been on heightened alert for attacks by home-grown radicals since 2014 and authorities have said they have thwarted a number of plots.
There have been several "lone wolf" assaults, including a 2014 cafe siege in Sydney that left two hostages and the gunman dead.
Today’s incident initially raised fears about the possibility of another attack.
Last year, in attacks claimed by the so-called Islamic State, trucks were driven into crowded pedestrian areas in separate incidents in Nice and Berlin, killing almost 100 people.
