Gardaí are trying to bring order to Portmarnock this evening, after crowds of young people arrived at the town's beach to take advantage of the good weather.
A spokesperson says there's an issue with public order in the area.
Reports from people in the area suggest the garda helicopter and a large number of squad cars have been dispatched.
Meanwhile, Irish Rail has confirmed that its 16.14 Drogheda to Pearse service had to stop at Portmarnock because a group of young people on board the train were causing problems for the driver, and other passengers.
A press officer says the youths were drinking and running amuck - Irish Rail's security team contacted the gardaí, who attended and removed the offenders. The train was delayed for 10 minutes.