Melbourne witnesses recount the horror: 'People were flying'

Witnesses of the Melbourne crash have described seeing "people flying" as a car deliberately drove into a crowd on a street packed with holiday shoppers.

Police said the crash outside Flinders Street station, in the city centre, was a "deliberate act".

Witnesses say the vehicle ran a red light, sped up and hit pedestrians in an area with a 40kph (25mph) speed limit.

"It just mowed everybody down, people were flying everywhere," one witness who identified herself only as Sue told local radio station 3AW.

Another witness called Jim told ABC TV: "The intersection was full of pedestrians and he just ploughed through.

"The only thing that slowed him down was him hitting pedestrians.

"There was no braking, there was no slowing down. Whether it was targeted or whether he had a heart attack, or was drunk, I don't know."

Lachlan Read, a 20-year-old, told the Herald Sun that 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," he added.

"There were bodies on the ground and people running up to them - it was mayhem."

Another witness, John, told ABC Radio Melbourne that he saw an "SUV coming at high speed".

"(I) really just heard the collision with people with bags and what must be shopping trolleys -- and I hope not prams," he said.

"I've really never seen anything like this before and I haven't stopped shaking."

Kyra Gillespie, among many to be told to get off trams near the area after the crash, told ABC News that "everyone is a little bit shaken up by the experience".

"Lots of people were phoning their loved ones to tell them they were OK," she added.

A woman called Nicola said she initially thought a bomb had gone off.

"I was waiting for the train and there was a big bang and lots of screaming," she told ABC News.

"I thought it must be a bomb. I could just see dust rising and we were told to get away and stay in the station."

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."

The driver of the car and a second man have been arrested and remain in police custody.