Attempts were made to start a fire in the harbourside toilets
Castletown Commissioners are urging residents to report any anti-social behaviour to the police.
It follows 'attempts' to start fires in multiple areas in the men's toilets in the harbourside block.
The local authority says the behaviour has 'knock on' effects as other facilities can't be left unsupervised.
People with information can call the Southern Neighbourhood Police on 822222 or can call the commissioners 825005.