Police were called to reports a woman had been heard screaming in Tan Yard Road at around 3.50am today (December 19).
Upon arrival, officers found a woman in her 20s who reported she had been attacked and raped by a man while she was walking on a footpath near the road.
The offender then made off from the scene.
Officers now want to speak to any eyewitnesses and are urging anyone with information to come forward.
"We are in the early stages of an investigation and enquiries are ongoing at this time to establish the exact circumstances," Det Insp Chris Naidu, of Lancashire Police, said.
"At this time we believe the victim travelled to the area in a taxi before the man assaulted her on a footpath close to Tan Yard Road.
"No arrests have been made and enquiries to identify the offender are ongoing."
The attacker has been described as white, aged in his 20s, with blonde hair.
He was dressed in dark clothing at the time of the attack.
Det Insp Chris Naidu added: "The woman is currently being supported by officers.
"We understand this is a very concerning incident for the local community and we would urge residents to remain vigilant.
"Patrols have been increased in the area and we have a dedicated team of officers handling the investigation."
Anyone with information can contact police on 101, quoting log number 0229 of December 19.
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