Emergency services are responding to an accident, including a ride at the Koni Beach Plager Park in PorthCol, Bridnda.
The children were among those on the Vesi worm ride, who were described on their website as a “small introductory roller coaster”, when the incident occurred.
Footage on social media shows adults to help many children away from riding.
The police have advised the public to escape from the area. The owners of the amusement park have been contacted for comment.
