A man has been arrested on suspicion of sexual assault with a police cordon put in place around the city's market at the weekend.
Officers were called to Haymarket in the centre of Norwich at around 9am on Sunday, July 10.
A man in his 30s was arrested following reports of a sexual assault.
He has been released on police bail until Tuesday, July 26.
A spokeswoman for Norfolk Police said: "Police believe this is an isolated incident.
"Officers are not seeking anyone else in connection with the investigation and enquiries are ongoing."
A police cordon and officers on watch were seen in the market throughout the rest of Sunday.
Forensic services were seen arriving mid-afternoon on Sunday.
An eyewitness said the police presence remained at the scene until the evening.
He said: "A lot of passers-by were asking what was going on.
"It was drawing considerable attention."
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