Officers were notified about the first incident - a stabbing at Bradford Park, Sydenham - about 10.15pm on Wednesday, March 18.
"The victim was transported to hospital for treatment and was released shortly after," a police spokesperson said in a statement.
The investigation indicated a second assault occurred earlier that evening on Colombo St, just south of Fisher Ave, about 9.30pm.
"Police believe the two incidents are linked. Police are working to identify the victim of the Colombo Street incident and would like to speak with them, as they may have information that could assist our investigation."
Anyone who was in the Bradford Park or Colombo St areas between 9pm and 10.15pm on Wednesday, March 18, can phone the police on 105.
"This includes anyone who may have witnessed suspicious activity or who has relevant CCTV or dashcam footage.
"Anyone with information is urged to contact police via 105, either by phone or online at police.govt.nz/use-105, selecting Update Report. Please reference file number 260319/6021."
