A 35 year-old man received stitches in his face after an assault in Buckland.
The man was taken to hospital with a cut to his face and was discharged last night.
A spokeswoman for the police said they believed a knife was used in the incident but they cannot confirm it.
She added: ‘We’re investigating an assault, which is alleged to have happened in Princes Street, Portsmouth, sometime between 8pm and 8.30pm last night (September 26).
‘We are treating this as an isolated incident at this time.
‘You may notice an increased police presence in the area, while officers conduct house to house enquiries.’
A spokesman for the South Central Ambulance Service said: ‘We were called at 20.19 last night with the caller reporting that an adult male had been assaulted and sustained facial injuries in the attack.
‘We sent an ambulance crew to the scene and after initial treatment the patient was then taken to the Queen Alexandra Hospital.’
Anyone with information is asked to call 101 quoting 44170374008