The incident happened in the Strand Park area of Ballywalter in Co Down on Sunday, October 28.
It was reported that sometime around 11.00 pm, a number of men forced their way into the property and assaulted a male occupant with hammers.
A 20 year old man was taken to hospital for treatment for his injuries which are not believed to be serious.
Detective Sergeant Rachel Miskelly is appealing for anyone who witnessed the incident or anyone with any information that can assist with the investigation to contact detectives at Newtownards on 101, quoting reference 1241 26/10/18.
Alternatively, information can also be provided to the independent charity Crimestoppers on 0800 555 111 which is 100% anonymous and gives people the power to speak up and stop crime.