A man has sustained a head injury as well as injuries to his arms and a leg following an assault by three masked men in Limavady on Sunday evening.
Police received reports at about 22:00 BST on Sunday that three men forced their way into a flat on Irish Green Street in the town.
The victim was treated for first aid by an officer before being taken to hospital in an ambulance.
Police are treating the incident as an aggravated burglary.
Det Insp McKenna described this as a “brutal attack” and said police are working to establish a motive for what occurred.
Police have appealed for anyone who was in the area at the time of the incident or who has any information to contact them.