A car ploughed into a crowd in Australia’s second-largest city on Thursday, injuring at least a dozen people, some of them seriously, officials said.

Witnesses said people were thrown through the air after being hit by the vehicle, which did not appear to be trying to slow down as it “mowed everybody down”.

Victoria state police said they had arrested the driver of the car after it “collided with a number of pedestrians” in downtown Melbourne at a busy intersection just after 4.30pm local time (0530 GMT).

A second man was also arrested by police, who have not yet said whether they believe the driver was acting deliberately.

Paramedics were “treating and transporting to hospital” 13 people, with some seriously hurt, ambulance officials said.

Sky News Australia reported that a pre-school child with a head injury was taken to hospital in a serious condition.

Police officers restrain a suspect as emergency services attend the injured after a car plows through pedestrians in Melbourne #verified pic.twitter.com/2SFK9oTiAK

— RTDigital (@RT_Digital) December 21, 2017

CAR RAMMING ATTACK IN MELBOURNE.

People trying to stop the SUV driver who ran over 19 people. 2 suspects arrested. pic.twitter.com/8URWHW2lvM

— Hananya Naftali (@HananyaNaftali) December 21, 2017

DEVELOPING: Driver arrested after car slams into pedestrians in Melbourne, Australia, injuring at least 14 in what officials are calling a "deliberate act"; it remains unclear whether the ramming is terror-related. https://t.co/Zeuum8x6rl pic.twitter.com/5V78O7Y0Wa

— World News Tonight (@ABCWorldNews) December 21, 2017