A man was attacked on the doorstep of his own home in Eastmoor.
Police are appealing for witnesses to the incident which took place on Parkhill Crescent, at around 3am on Friday, October 17.
The 40-year-old victim had opened his door after hearing a noise and shouting outside.
He was confronted by three men who asked if another man still lived there.
He tried to scare the men off but one of them attacked him.
The victim was left with a minor head injury.
But before the three men left they also damaged the kitchen window.
PC David Pickering of the neighbourhood police team (NPT) said: “We are investigating this incident and have stepped up high visibility patrols in the area.
The suspects for the offence were three white men, all between 5ft 9ins and 6ft 2in tall and in their late 20’s.
“Anyone who saw three men behaving suspiciously in the local area at around the time of the incident or has any information is asked to contact myself at the NPT, on 101. Information can also be given anonymously to Crimestoppers on 0800 555 111.”