Armed police surrounded a house in Southampton on Friday after reports that burglars armed with a gun had injured someone inside.
Police were called to Carlton Road at 2019 BST following reports that two men had entered the house.
Officers were initially told that a man and a woman were inside and the man had suffered a head injury caused by a gun.
When police arrived the intruders had fled and the man's injury was found to be a cut.
Armed response teams remained at the scene until 2150 BST and the house was searched.
The 21-year-old man received medical treatment at the scene for a cut to his head, but was not taken to hospital.
The woman, aged 22, was not hurt.
Detectives are now carrying out forensic, house-to-house and CCTV inquiries to trace the two men.
Det Insp Simon Baker said: "Police would like to reassure the community that there is no evidence to suggest any wider risk to the public.
"Officers are treating this report as an isolated incident at this time."