Two men wearing hoods and carrying a hammer broke into a property and assaulted two men and a woman.
Detectives are investigating the report of the aggravated burglary at a house in the Old Market Square area of Newtownards.
It happened in the early hours of this morning (Sunday, December 16) at around 1:45am
A fourth man jumped from a first floor window to escape the intruders.
He was taken to hospital for treatment to injuries sustained as a result of this.
Detectives are appealing to anyone who noticed any suspicious activity or anyone who has information that could assist police with their enquiries to contact them at Bangor on the non-emergency number 101, quoting reference 166 16/12/18.
Alternatively, information can also be provided to the independent charity Crimestoppers on 0800 555 111.