Police launched an urgent investigation yesterday (Tuesday, October 12) after four women were molested by the man as they walked alone.
Detectives shared CCTV images of a man who has now been identified. Lancashire Police say the man has not been arrested but is "assisting us with our enquiries".
The force said it is not looking for any other suspects in connection with their investigation.
A police spokesman said: "Officers investigating a number of reports of a man attempting to grab women in Blackburn have identified a man they wanted to speak to and he is assisting us with our enquiries.
"He has not been arrested but we are not looking for anyone else in connection with our investigation.
"As a precaution, increase patrols will remain in place over the coming days."
What has happened?
A woman was sexually assaulted after a man approached her and asked for a lighter in Whalley Old Road at around 5.55am on Monday (October 11).
The woman called 999 but the man continued to follow her, police said.
The call handler managed to direct a passing patrol car to her location, but the suspect escaped the area "despite a number of patrols quickly attending the area."
Yesterday (Tuesday, October 12), shortly after 5.45am, police were called to Cathedral Square after a woman reported being grabbed by a man as she was walking to work.
Officers said the victim managed to fight the man off before screaming and running to a place of safety.
The incident happened in an alleyway between Blackburn Cathedral and Blackburn Market.
Later that morning, at 9.2am, a man reportedly exposed himself to a woman in East Park Road before verbally threatening her.
Five minutes later, a woman reported seeing a man staring at her as he was walking in her direction in West Park Road.
As she stood aside to let him pass, he brushed up against her and then walked off.
Det Insp John McNamara said: "Although we are still working to understand the suspect's behaviour, we realise the public will be concerned by it.
"Reassurance patrols have been increased in the areas affected and they will continue in the coming days."