Police in Derry have launched an appeal after a man was attacked in the Guildhall Square area of the city last night.
It's understood a large group of youths were involved in the incident.
The attack happened at approximately 9.30 last night.
One male was arrested at the scene.
Police are keen to speak to anyone who may have witnessed the incident to contact them.
They are particularly keen to speak to a witness who helped the victim to safety.
Anyone with information is asked to contact the 101 non-emergency number or information can be provided through Crimestoppers on 0800 555 111.