Emergency medical workers offer aid to victims struck by a vehicle in Melbourne, Australia. Picture: Australian Broadcast Corp. via AP

Sydney - The man accused of driving a car that rammed into a crowd of pedestrians in Melbourne on Thursday appeared in court Saturday charged with 18 counts of attempted murder.

Saeed Noori, 32, who came to Australia as an Afghan refugee, did not apply for bail and is due to appear in court again on Wednesday. He is also charged with one count of conduct endangering life.

When Noori saw his mother in the court room he put his head in his hands and became emotional, the broadcaster ABC reported.

His mother cried and rocked back and forth when she saw her son enter the courtroom. Security warned her when she tried to approach him in the dock. She did not comment to media after the hearing.

Melbourne Magistrate's Court was told the motivation for the attack remained under investigation, and further charges were being considered.

Noori's lawyer told the court his client's mental and physical health would be an issue while he was in custody. The magistrate ordered a psychiatric assessment.

A damaged vehicle is seen at the scene of an incident on Flinders Street, in Melbourne. Police arrested a driver after a car drove into pedestrians on a sidewalk in central Melbourne. Picture: Joe Castro/AAP Image via AP

Eighteen victims were taken to hospital after the car accelerated and ran a red light to slam into pedestrians crossing the road near Flinders Street Station in central Melbourne at 4.40pm Thursday.

On Saturday twelve people remain in hospital receiving treatment, including an off-duty police officer who ran to the vehicle when it came to a stop and detained the driver.

The court was told three people are still in a critical condition. They are two South Korean men aged in their 60s and an 83 year old Melbourne man.

Nine of the injured were foreign nationals coming from South Korea, China, Italy, India, Venezuela, Ireland and New Zealand.

Earlier, police said there was no evidence the driver of the car was linked to terrorist groups, but that he did make "rambling" comments about Allah and poor treatment of Muslims during initial discussions after the incident.

Acting chief commissioner of Victoria Police Shane Patton said there was no evidence the attack was premeditated or terror-related, the Melbourne Herald-Sun newspaper reported Saturday morning.

Pedestrians walk past as police and emergency services attend the scene of an incident involving a vehicle and pedestrians in Melbourne. Picture: Kaitlyn Offer/AAP Image via AP

"We still haven't ruled out terrorism. We continue to explore it. It's about exploring the evidence and the evidence will ultimately take us where it does. If that means it's a terrorist event, so be it."

Earlier, police said the man had a history of mental health issues and drug abuse.

At a press conference on Saturday, Victorian Premier Daniel Andrews said there would be an increased police presence at events following the "cowardly act" on Flinders Street.

"Victorian police have the resources and the resolve to do everything that needs to be done to keep the community safe," he said. Extra police will be at Carols by Candlelight, the Boxing Day cricket test against England, and New Year's Eve.