The incident happened on Tuesday, between 11pm and 11.30pm in Lychgate Walk, a footpath that runs through the church grounds between King Street and Church Street.
Police inquiries are ongoing and witnesses are urged to come forward.
Detective Sergeant Jon Taylor said: “This is a popular footpath between King Street and Church Street.
"We know that people may have helped the victim and we are appealing for them to contact us to help us with our investigation.
"We are also interested to identify and speak with a man who was seen running away from the area.
“I would also ask anyone who was in the area that may have seen something, including motorists in the area that may have dash-cam footage during the evening of Tuesday, June 8 between 11-11.30pm to contact us with any information.”
Contact West Mercia Police online under the Tell Us About section at westmercia.police.uk or call 101.
Alternatively, contact Crimestoppers anonymously on 0800 555111 or at crimestoppers-uk.org