Sydney - Australian police have arrested a man who stabbed a woman to death and chased several people in central Sydney on Sunday before passers-by could control him, police and witnesses said.

Police said a 21-year-old man from Sydney, suffering from a mental illness, was believed to have killed a woman of about the same age in a housing unit before coming down the street with a knife.

New South Wales Police Commissioner Mick Fuller told reporters that the man had no known links to terrorist organizations, but had a USB data carrier with details of attacks by white supremacists calling for victims in the United States and New Zealand.

He added that the attack, which he described as a "horrific massacre", "is not classified as a terrorist incident," adding that the attacker had no links to terrorist groups and was acting alone. Police said they found a 21-year-old woman dead in an apartment, while another 41-year-old woman was taken to hospital with a stab in her back. She said the woman was in stable condition.

Police did not say how the young woman died, but said the man was responsible for the attacks.

Police said they arrested the man, but did not confirm a link between the two incidents.

A police spokeswoman told AFP the young woman's body had been found in Sydney's central business district, where the stabbing took place, but police were still "investigating" to find out what happened.

"A man with a large kitchen knife chased many people in a busy business district," said witness Megan Hayley. "Five or six other people in the background were chasing him trying to deter him." They arrested him and took control of him, ”he said, using chairs and a plastic box.

Scenes aired by Australian media showed the man jumping on the roof of a car with a knife shouting "Kill me."