A young man has attempted to stab a number of people in Sydney's central business district with one woman rushed to hospital covered in blood.
The body of a woman has been found inside an apartment in Sydney's CBD and detectives are working to establish if her death is linked to a nearby stabbing incident.
The attacker, who was seen jumping on the bonnet and roof of a Mercedes, stabbed a woman in the back before he was held down with chairs and a milk crate by onlookers, police said.
A statement from NSW Police said: "Inquiries are underway after the body of a woman was found in side a unit on Clarence street, Sydney, about 3.15pm today".
"A short time later, members of the public detained the man before police attended and arrested him", NSW Police said in a statement.
Police have asked people to avoid the area.
"A number of members of the public physically restrained the offender".
"These people are heroes, and I want to acknowledge that". They were courageous and I can only use that word seriously. "They were significantly courageous people".
One witness, Marcon, told the Daily Mail Australia: "He was trying to smash a driver side window of a random vehicle with the knife".
Witness Zak Barry said he saw the man fall down on York Street "and as he's falling he dropped a kitchen knife".
"My brother and I ran across here and we managed to get a grip along with other guy and we have a grip of him and restrained him fully".
"There is a police operation that is ongoing in the CBD", a police spokesperson said.
"He ran all the way back to near my work where a lot of others had cornered him for the police".
"The male offender was on his own and there was no other person complicit at this stage".
Jack Huddo, who purportedly witnessed the incident, wrote on Twitter: "A random dude just started stabbing people in the city right outside where we were having lunch".
He said the crowd was "shaken up, that's for sure".
Video posted on Twitter shows the man yelled at police: "F***ing shoot me in the f***ing head" before he was wrestled to the ground by bystanders and a milk crate was placed over his head.
"He just stabbed a chick in broad daylight".
The attacker appeared to be agitated and had blood splattered on his shirt and was carrying a large knife, an eye witness told radio station 2GB.
"It is believed there is no further threat to public safety", police said.
NSW Police arrested the man, who was barefoot and appeared to be a highly-agitated state.