The unidentified man had also tried unsuccessfully to stab other people, police said, in an incident that brought the central business district in Australia’s largest city to a standstill in the early afternoon.

“We have a female person with a stab wound to the back currently being treated by paramedics and is en route to a Sydney hospital,” Police Superintendent Gavin Wood told reporters in Sydney.

He said the woman’s injuries were not life-threatening.

Wood also said the attack appeared to be unprovoked but police were keeping an open mind.

Video footage on Twitter showed a young man running across a city intersection and jumping onto the hood of a car, waving what appeared to be a knife.

The man fell to the ground when the car moved and was confronted by a person holding a chair, the video showed.

Other footage showed the man pinned to the ground by several people holding two chairs and a milk crate on top of him.

A woman who answered the phone at a Subway store near the scene told Reuters: “We saw the person with a knife over there bleeding.”

“The cops are here and they blocked the road right now, so we can’t go outside. They said: ‘It’s a crime scene, you can’t come out’,” said the woman, who declined to give her name.

Police said the man was acting alone.