An armed man has been arrested in central Sydney after stabbing a woman and being detained on the street by members of the public, authorities say.
A second woman has been found dead inside an apartment building on the same street but it is unclear whether this is connected to the incident.
Police said the man attempted to carry out further stabbings and there were “multiple crime scenes”.
Video footage shows the suspect shouting “Allahu Akbar” and “shoot me”.
He jumps on a car wielding a knife as another man confronts him with a wicker chair.
The incident unfolded at about 14:00 local time (04:00 GMT) on Tuesday near Clarence St and King St, a busy area in the city centre.
The injured woman was taken to hospital in a stable condition. Police said there was no ongoing threat.
Police said they were investigating whether the body found in the apartment was linked to the incident.
The motivation for the attack is not yet known, said Supt Gavin Wood of New South Wales Police.
“It would appear at this stage it is unprovoked, but we are keeping a very open mind as we move forward,” he said.
Videos posted online show a man running through the streets brandishing a knife, before people attempt to stop him and eventually tackle him to the ground.
Other images show the suspect being pinned down with a chair and a milk crate, then being taken away by police.
Supt Wood praised those who had intervened in the “extremely dangerous and hostile” situation, saying their actions had helped capture the man.
“They were significantly brave people,” Supt Wood said.
Authorities urged people to avoid the area. Police said they would release more information as it became available.