Australian leaders have reacted to the car rampage in Melbourne's CBD that has killed four people, including a young child, and injured at least 15 others.
Among those to comment was Melbourne Lord Mayor Robert Doyle, who was giving a press conference as the attack happened and saw it unfold.
"It was a moment of horror" Mr Doyle told radio station 3AW.
"We saw the car disappear into a crowd of pedestrians on the footpath on Swanston Street".
"I'm normally not lost for words."
He labelled it as a "wanton act of destruction".
"It is very difficult to believe these sort of things could happen right in front of you in the city," Cr Doyle said.
The council released a video of his comments on Friday afternoon.
Australian prime minister Malcolm Turnbull said he was praying for the families involved.
"Our prayers and deepest sympathy are with the victims and their families of this vicious criminal attack," Mr Turnbull said.
Opposition leader Bill Shorten said it was a horrific incident.
"Horrific scenes in Melbourne this afternoon, he said. Hearts go out to all those who've been hurt," Mr Shorten said.
Meanwhile, former Victoria Police commissioner Christine Nixon said she was at the scene and the car missed her by barely a metre.
She saw an overturned pram unattended and went to check that it was empty, she told ABC Radio in Melbourne.
According to her account, the mother then walked up and asked: "Where's my child?"
Ms Nixon responded: "I don't know. The child is not in the pram."
"I just stood there for 15 or 20 minutes directing traffic. No one disobeyed my instructions," she said.
Victorian Premier Daniel Andrews said in a press conference that they "have apprehended the person involved in this terrible criminal act."
He said he was proud of Victoria's emergency services for the way they responded to the attack, as well as members of the public who stepped in to help and support each other.
"We can be confident that we are stronger than this evil criminal act," he said.