A teenage girl was taken to hospital with head injuries after an alleged fight broke out near the Millennium Park toilets on Sunday night.
Police say a group of teenagers were there at around 9pm on Sunday 22 August when the fight happened, with at least two involved.
A 15-year-old girl was arrested and released on bail pending further enquiries.
Police want to speak to anyone who saw, or has any information on, what happened.
The girl arrested had dyed hair and was wearing a dark coloured hoody, light grey joggers, and Nike trainers.
The injured girl was wearing dark clothes and carrying a skateboard.
It's thought both girls knew each other.
Anyone with information is asked to call police on 612612 or Crimestoppers anonymously on 0800 555 111.
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