The man was seen running along Lancaster Road
A 19-year-old woman has been sexually assaulted as she walked home through Preston city centre after a night out.
The victim was attacked at the junction of Jackson Street and the Flag Market at about 0520 BST on Saturday.
She was grabbed from behind by a man who then ran away in the direction of the covered market.
Police have released a CCTV image of a man they want to speak to in connection to the incident and have appealed for information.
The image shows a man running along Lancaster Road at around the same time as the attack.
'Rare' incident
Det Insp Jonathan Holmes, of Lancashire police, said: "This was a serious assault on a lone female and we need to find the person responsible.
"I would appeal to anybody who recognises the man in the CCTV to contact police.
"Similarly, I would urge the man himself to come forward as he could hold vital information which can help with this investigation.
"Whilst incidents of this nature are rare, I would ask people, particularly females, to be sensible and take the necessary precautions when making their way home after a night out."
Police described the attacker as Asian.
