Two men have been arrested on suspicion of raping a woman outside a church.
The woman, who is in her 30s, was attacked outside St Mary's on Churchgate in Stockport town centre, said Greater Manchester Police, who were called at about 08:05 GMT.
She has been taken to hospital and is being supported by specially trained officers.
Two men - aged 44 and 57 - are being questioned. Anyone with any information is asked to contact police.
Det Insp Julia Bowden said: "Whilst we believe this is an isolated incident and have two men in custody, our investigation is in the very early stages and our inquiries will continue at the scene throughout the afternoon.
"I would encourage anyone who thinks they might have even the smallest piece of information that could assist our investigation to please get in touch as soon as possible."