Police say a woman in her 50s has suffered serious facial injuries during a sexual assault in Londonderry.
It happened on the Lecky Road in the early hours of Sunday morning.
A man in his 30s, has been arrested on suspicion of related offences and he remains in police custody at this time.
The woman was approached by an unknown man who pulled her into a nearby alleyway, where he sexually assaulted her, repeatedly hit her face, and banged her head off a wall.
The Police Service of Northern Ireland (PSNI) said: “She sustained serious facial and other injuries as a result of this terrifying ordeal that she was only able to escape from after her attacker let her go.
“The woman was able to then raise the alarm for help, and the suspect fled the scene on foot.”
The woman required hospital treatment for her injuries.
Police have asked anyone who was in the area at the time of the incident to contact them.