Police in Southampton are seeking two key witnesses following a serious sexual assault in the city.

A 44-year-old woman was attacked by a man as she sat on a bench in Guildhall Square, opposite the Civic Centre.

The offender is described as a white man in his 30s to early 40s, of medium build, with shaved hair. He was wearing blue jeans and a mauve shirt.

A 33-year-old man from Southampton has been arrested and bailed in connection with the incident between 1am and 1.20am, on Saturday.

Police are appealing for any witnesses to the incident, and are particularly keen to hear from two men who assisted the woman following the attack, directing her to the police. It's believed they may have spoken to the offender at the time of the attack.

Anyone with information is asked to contact Shirley CID on 0845 045 45 45, or anonymously via Crimestoppers on 0800 555 111.