Paramedics treated a man for a stab wound in St James Square on Tuesday night (Dec 14).
It happened at around 10pm - police were called to a disturbance on the square, where they found the victim who was later taken to hospital.
He remains in a stable condition.
Detective Constable Tom Carpenter said:
“We received a number of calls from concerned residents in relation to this matter and we understand the impact incidents such as these have on the community.
“A full investigation is ongoing to confirm the exact circumstances of what happened and identify those responsible. There will also be an increased police presence in the area over the coming days to provide visible reassurance.
“Anybody who witnessed the incident or has relevant CCTV, doorbell or dashcam footage, is asked to contact police online or by calling 101, quoting serial 1316 of 14/12.”