An unidentified man hit with his car a crowd of pedestrians early Friday, killing three people and up to 20 were injured in central Melbourne, Australia, according to Victoria Police.

The man was arrested soon after and "the situation is now contained", police said.

The incident was not terror-related, said Victoria Police Acting Commander Stuart Bateson.

He said police believed the incident was linked to a stabbing in Melbourne's south-east early on Friday.

Footage broadcast on local media showed a maroon car driving in circles in front of nearby Flinders Street railway station.

Mr Bateson told reporters that police believe the driver "deliberately drove into the crowd".

A witness said she saw pedestrians try to get out the way as the car mounted a footpath, according to BBC.

"It hit a few people there outside the offices and convenience store and sent them flying into the air, then kept driving," the witness said.

"It hit some more further up the path. I didn't know what was happening at first. People were screaming and there was a lot of sound and dust - I thought a building was coming down."

Melbourne's Royal Children's Hospital confirmed it was treating 10 patients from the incident. St Vincent's Hospital said it was treating up to six patients.

The Australian Open tennis event, being played about 2km (1.2 miles) away, was unaffected, police said.

Lord Mayor Robert Doyle said he was standing outside Melbourne Town Hall when he saw the car drive "at speed" towards Bourke St Mall.

"It is very difficult to believe that these sorts of things can happen right in front of you in the middle of our city," he said in a video posted online.

"Spare a thought particularly for those families - the loved ones of those affected - and let's try and take care of each other."

Police asked people to avoid the city center.