A woman was raped by ‘several’ men while she was in a doorway in the middle of Chichester.
The 40-year-old was standing at the entrance to the now empty Argos building in South Street when she was attacked on the evening of Wednesday June 19.
The men are all described as in their 30s, and slim with tanned skin.
Sussex Police said the victim was receiving specialist support and advice from officers while detectives try to establish the full cirumstances of what happened.
The crime was first reported to police on Monday, and no arrests have been made.
Detective Inspector Sally Arbuckle, of the West Sussex Safeguarding Investigations Unit, said: ‘If you were out and about in Chichester city centre that Wednesday evening, June 19, and saw any suspicious activity, especially towards the bottom of South Street near the railway station, we would like to speak to you.
‘Officers will be in South Street this Wednesday evening, June 26, one week on from the crime, so if you are there and can help please speak to them.
‘If you can help in any way please also contact us online or by calling 101, quoting Operation Keyhaven.
‘This was an isolated but very distressing incident involving a vulnerable person who is part of the local street community, and we need to trace those involved.’