Two held after car 'mows down' pedestrians outside Australia train station
Witnesses described "people flying everywhere" as a white car was driven at crowds outside Flinders Street station in Melbourne just after 4.30pm (5.30am GMT).
Images from the scene showed a number of people receiving medical attention, while a white Suzuki SUV appeared to have crashed to a stop.
Police said they had "saturated" the area with officers as paramedics transported 13 people to city hospitals, while two people were being assessed by paramedics at the scene.
A woman called Sue told 3AW radio: "As it (the car) approached this intersection... it just mowed everybody down, people were flying everywhere."
Social media images appeared to show a young man in jeans and a T-shirt being arrested by three police officers on the steps of the station, although it was unclear if he had been in the car.
Sky News said the driver of the SUV was of Middle Eastern appearance and that he was wrestled to the ground and handcuffed following the crash.
Lachlan Read told the Herald Sun the whole incident lasted about 15 seconds.
"It was bang, bang, bang. It was just one after the other.
"The last bang the car stopped," the 20-year-old said. "There were bodies on the ground and people running up to them - it was mayhem.
"It is definitely something you don't expect to see on Flinders Street."
It was the first week of school summer holidays in Victoria, and the area was busy with Christmas shoppers.
Elton Hindoli, who works at an off licence by the scene of the incident in Elizabeth St, told the Herald Sun that a man who was pulled from the car appeared to be unconscious.
"A girl came into the shop and she was very upset," he said.
"She said a guy in a big car had hit about six people.
"It wasn't clear if the driver was hitting them on purpose or not.
"He hit the people then crashed into the tram area in the middle of the road."
A man who was working in a nearby shop and was at the scene before emergency services arrived told the Australian Associated Press: "There was no screaming, just people lying there."
Victoria Police said officers had "saturated" the city's central business district following an incident where a car had collided with a number of pedestrians on Flinders Street.
"The driver of the vehicle and a second man have been arrested and are in police custody," the force said.
"A number of people were treated at the scene for a range of injuries and have been transported to hospital.
"A crime scene has been established and all vehicular and pedestrian traffic are advised to avoid the area."