A 20-year-old man sustained a suspected fractured wrist and swelling to his head and face after a serious assault by up to 10 people in the Skegoneill Avenue area of north Belfast last night.
It was reported that at around 6.35pm the young man was knocked to the ground and struck with what is believed to have been a hammer.
A 17-year-old male was arrested a short time later on suspicion of grievous bodily harm and is currently in custody assisting police with their inquiries.
A PSNI spokesman said it was believed that up to 10 people were involved in the incident and Detective Inspector Mark McHaffie is appealing for anyone who was in the area of Skegoneill Avenue or Jellicoe Avenue yesterday evening and who witnessed the assault or anyone with any information that can assist with the investigation to contact Detectives in Musgrave Police Station on 101.
Information can also be passed anonymously via the independent charity Crimestoppers on 0800 555 111.