Pictured: The two men arrested after car hit pedestrians in Melbourne

These are the first images of the two men who have been arrested after a vehicle ploughed into pedestrians in Melbourne's CBD.

The incident unfolded on Flinders Street shortly after 4.30pm as a white 4WD mowed down pedestrians, injuring 14, with two critical including a preschool aged child.

Two men (pictured) from inside the white 4WD were arrested by police. Source: 7 News

The two men are yet to be charged while police said it was too early to comment on whether the incident was terrorism related, they have said they believe it was a deliberate act.

“We believe based on what we have seen that it is a deliberate act," Commander Russell Barrett told reporters.

"The motivations are unknown, it is still the early days of the investigation."

Police have confirmed the two men are aged 19 and 24.

The incident comes just 11 months after six people were killed in a similar incident in nearby Bourke St.

Among those rushed to hospital is a pre-school aged child suffering serious head injuries.

One man was seen sitting against a wall talking to police. Source: AAP

Witness Jim said the 4WD was travelling west along Flinders Street at up to 100km/h.

"The intersection was full of pedestrians and he just ploughed through," he told ABC TV.

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

The other man was dragged from the 4WD. Source: AAP