A man in his 40s has been seriously injured during a stabbing in Belfast city centre.
It happened on a footbridge at the back of the Waterfront Hall at about 11:00 BST on Friday.
Police said they are working to establish a motive for the attack and are appealing for information.
Detective Sergeant Kyle Corrigan said: "Enquiries are under way and officers are working to apprehend those responsible.
"I'm appealing to anyone who may have been in the area of the blue metal footbridge at the rear of the Waterfront Hall this morning," he said.
"Did you see anything suspicious? Did you see the incident, or any one running away from the scene?"
Anyone with information has been asked to contact 101 or Crimestoppers.