Barmouth police are asking residents if they know what their children are getting up to at night.
This follows more reports of criminal damage and anti-social behaviour in the Barmouth area.
“Youths have been seen knocking and kicking violently on doors and running away,” a North Wales Police spokesperson said.
“You may think it's a harmless TikTok craze but damaging property and frightening residents is totally unacceptable.”
The spokesperson added: “Our Neighbourhood Policing Team in Barmouth are actively looking through CCTV and ring doorbell footage to identify any youths involved.
“We would also urge all parents to play their part by ensuring they know where their children are and who they are spending time with!”