The police warned on Tuesday that no can be asked to pay a fine on the spot.
In a Facebook post, the police said they had received reports that unidentified individuals have been stopping people in the street and asking them to pay a fine on the spot for not wearing a mask.
Fines are never paid on the spot, the police said. They can be paid online, at local council offices or after tribunal hearings.
The police urged anyone encountering people demanding payment of fines to report at the nearest police station or via the Crime Stop number 119.