With AAP.

UPDATE: The victim of the Sydney CBD attack has been identified as 24-year-old Michaela Dunn.

Just before 3pm on Tuesday afternoon, reports emerged that multiple people had been stabbed in Sydney’s CBD by a young man.

Police were on the scene at King Street and Clarence Street and quickly instructed people to avoid the area.

Now, it looks as though the death of a woman in a Clarence Street unit is linked to the stabbing. She was found at 3.15pm on Tuesday.

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At 2.45pm, a police spokesperson said there was a police operation ongoing in the CBD.

Police operation King & Clarence St, Sydney CBD. Please avoid the area. More to come…

— NSW Police Force (@nswpolice) August 13, 2019

Witnesses on Twitter said multiple people had been stabbed, and captured acts of bravery from members of the public who tried to stop the assailant.

So insane! A random dude just started stabbing people in the city right outside where we were having lunch. I saw people running so I ran towards him with a few other guys.

He ran all the way back to near my work where a lot of others had cornered him for the police! #sydney pic.twitter.com/SQvqfDRz88

— JackHuddo (@JackHuddo) August 13, 2019

Just witnessed incredible bravery from members of the public and ⁦ @FRNSW ⁩ officers chasing down a man on a stabbing rampage in Sydney’s CBD. He is now under arrest. ⁦ @7NewsSydney ⁩ pic.twitter.com/wNKatejHVp

— Andrew Denney (@Andrew_Denney) August 13, 2019

Footage from 7 News showed the man climbing on a black car holding a knife, before flashing to footage of the man being held down by members of the public.

Just after 3pm, Superintendent Gavin Wood told reporters it’s alleged that the offender attempted to stab several people – including a woman, who was stabbed in the neck. She was located inside Hotel CBD, and taken to hospital in a stable condition.

What we know about the Sydney CBD stabbing attack: https://t.co/e3Kd2SoOEs #9News pic.twitter.com/tc9efjn7Kl

— Nine News Gold Coast (@9NewsGoldCoast) August 13, 2019

Witnesses have toldAAPa young man armed with a 30-centimetre kitchen knife had been yelling religious statements.

Police say it’s been reported he was yelling “Allahu Akbar”.

Witness Zak Barry said he saw the man fall down on York Street “and as he’s falling he dropped a kitchen knife”.

Paul O’Shaughnessy, 37, said his brother Luke, 30, saw a man with a balaclava wielding a knife.

The pair chased the man and then managed to get a grip on him with the help of a third person.

“He’s got blood all over him … shouting religious statements,” Mr O’Shaughnessy told reporters.

“A number of members of the public physically restrained the offender,” Supt Wood said.

Witnesses have described incredible scenes as a group of heroic bystanders chased down a knife-wielding attacker and pinned him down with a milk crate in shocking scenes in the Sydney CBD. https://t.co/WoI0jgiUUc

— The Daily Telegraph (@dailytelegraph) August 13, 2019

“I want to acknowledge those members of the public who got involved. They were significantly brave people.”

Supt Wood said it appeared Tuesday’s attack was unprovoked and the man had acted alone.

A caller to 2GB radio confirmed the young man had been tackled to the ground.

“He’s definitely been detained … he’s been taken away,” the caller, Tom, said.

Video of man being arrested after police operation in Sydney’s CBD on King and Clarence St. #SydneyCBD #BREAKING pic.twitter.com/cTs063eKM5

— Daniel Timms (@deadsetdaniel) August 13, 2019

An Uber driver said he saw people running away “and next thing I see this guy jumping over the car, he went over the bonnet, and went on top of the car”.

A man, whose car was jumped on by the #Sydneystabber has spoken to #9News about the terrifying moments as they unfolded. pic.twitter.com/3vlspQqEh6

— Nine News Sydney (@9NewsSyd) August 13, 2019

“He had a little bit of blood on his shirt,” the driver told 2GB.

NSW Police have set up a series of roadblocks in the area.

“A number of crime scenes have been established,” a spokesperson said.

SYDNEY CBD: Motorists should stay away from the CBD due to an ongoing police operation. King St is closed btwn Clarence and York Sts. Clarence St also closed northbound btwn Market St & King Sts. Avoid the area. https://t.co/ijtT0AQVce pic.twitter.com/V4NlU5rb6x

— Live Traffic Sydney (@LiveTrafficSyd) August 13, 2019

Supt Wood said there was no ongoing threat after the man’s arrest.

More to come.