19 people have been injured after a car ploughed into pedestrians in Melbourne

Australian police said on Thursday they have arrested the driver of a vehicle that ploughed into pedestrians at a crowded intersection in the southern city of Melbourne, with as many as 19 people injured.

Police in Australia's second-largest city did not give any possible motive for the incident, which took place at just after 4.30 p.m. local time. It had chilling echoes of a similar case when four people were killed and more than 20 injured in the same city in January.

Ambulance Victoria said in a statement it was assessing 13 people at the scene. Two people had been taken to hospital, including a pre-school child with a head injury.

Major streets in cities such as Melbourne and Sydney have been packed with holiday shoppers this week.

"Extent of injuries are not known at this stage," Victorian state police said of Thursday's incident on their official Twitter account.

Police said the January incident was not terror-related, although it led to Melbourne and other cities ramping up security measures in pedestrian areas in major cities.

That incident followed a series of terror-related attacks in Europe where vehicles were used to mow down pedestrians.