Police were called to reports of a large gathering of youths in Burry Port at around 6.05pm on Wednesday.
Dyfed-Powys Police officers are investigating damage caused to a car during the gathering of around 200 youths.
Police were called to the incident over concerns over underage drinking and antisocial behaviour as the crowd grew after being advertised on social media.
Officers used a dispersal order to move the young people on and worked with our partners from British Transport Police to make sure they made their way home.
Sergeant Ben Ashton from the Llanelli Neighbourhood Policing Team said: “Officers responded promptly to this incident to reduce further antisocial behaviour. We are currently investigating reports of criminal damage caused by some of those involved.
“Underage drinking is dangerous and makes teenagers vulnerable to harm.
“We would like to remind parents of their responsibilities to be aware of where their children are and what they are doing.
“It is an offence to buy alcohol for anyone under the age of 18, and anyone caught doing so will be dealt with accordingly.”
High visibility patrols are planned over the bank holiday weekend.
