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
Owen Smith has been sacked from Jeremy Corbyn's shadow cabinet after calling for a new EU referendum.
The former Olympian turned coach has three athletes heading to Australia to compete in the Games.
After facing calls not to try to outflank Labour on the left, the party's leader calls for unity to achieve the aim of ruling Wales.