A woman is in Wellington Hospital with serious injuries after a daylight assault in a park.
Detective Senior Sergeant Warwick McKee said about 11.45am emergency services were called to a report that a woman had been stabbed in Brooklyn's Central Park.
Armed police attended the scene and cordons were set up.
"On arrival a woman with serious injuries was located and taken to hospital. The alleged offender, a man, had left the scene and has not yet been located. At this stage it is believed the man was unknown to the victim."
Det Snr Sgt McKee said cordons were in place around the perimeter of the park while a scene examination took place, but by about 4.30pm they had been stood down.
Police were calling for witnesses and Det Snr Sgt McKee said: "We also want to remind the public, particularly people walking alone, to be aware of your surroundings and call 111 immediately if you see anything suspicious".