A woman was dragged into an alleyway before being sexually assaulted in Rochdale.
The victim, who is in her 20s, was walking along Grimshaw Lane in Middleton when a masked man approached her and dragged her into an alley.
He then assaulted her on the floor, police said.
The woman screamed out for help before managing to break free.
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She wasn't hurt, but was left shaken following the 'traumatising attack'.
The man ran off down the alley, towards a nearby field.
Police say he was white, in his 30s, had a 'very skinny' build and was round 6ft.
He had a 'large ginger beard' and was dressed in black tracksuit bottoms, a black hoodie and a a hat.
Officers said he is understood to have a local accent and was initially wearing a black face mask before taking it off.
No arrests have yet been made. Enquiries are ongoing.
Detectives are appealing for anyone who witnessed the incident - which happened at around 10.35pm on Sunday, October 25 - to come forward.
They particularly want to speak to anyone who recognises the description of the man.
Detective Inspector Mark McDowall, of GMP's Rochdale CID, said: "This was a traumatising attack and we are ensuring that the victim receives all the necessary support that they need at this time after the shock of this incident.
"This assault took place just off a busy road and I am hopeful there will have been many people passing through the area in the moments before this attack who may recognise the description of the man and who may have dash cam footage from the area that could aid our enquiries.
"Patrols have been stepped up in the area as a response to this incident and I reassure the public that we will do all we can to try and catch the man responsible for this attack and get him taken off our streets."
Anyone with information is asked to call police on 0161 856 8441 quoting incident number 2998 of 25/10/2020. Details can also be passed to the independent charity Crimestoppers on 0800 555 111.