It comes as officers put in a cordon in Somers Road between the junctions of Rivers Street and Lower Forbury Road.
Police were called at 1.32pm after a man was ‘seriously assaulted’.
The victim, in his 30s, was found with a ‘stab wound to his abdomen’.
He is in Queen Alexandra Hospital but his injuries are not thought to be life-threatening, police said.
A Hampshire police spokeswoman said: ‘An investigation into the incident is underway and officers remain in the area conducting enquiries.
‘We would urge anyone with concerns to speak to patrolling officers.’
Anyone with information should call police on 101 quoting 44210310946.
The site is close to the scene of a fatal crash in Winston Churchill Avenue on Tuesday.