Dyfed Powys Police are investigating an assault that happened in Llanelli between 11pm and midnight on Saturday.
A 12 year old girl received minor injuries in the incident.
The suspect is described as a white man aged 30-35 with short spiky dark hair. He was wearing a Scarlets rugby top and light grey tracksuit bottoms.
Anyone with information should contact Llanelli CID.
More top news
A group of children from Colwyn Bay may have hopped into the unofficial record books by creating a local hopscotch course.
A vulnerable missing man was forced to work 15-hour days with no pay for 13 years, a trial at Cardiff Crown Court has heard.
Adrian Masters and Andrea Byrne present Monday's special edition from Edinburgh and Cardiff.