Police have been targeting drug dealers in a West Yorkshire town by taking a sniffer dog into pubs and clubs to find illegal substances.
The dogs were taken into buildings in Bingley as part of a purge on drugs and potential disorder, senior officers said.
Police arrested one person for possession of what was thought to be class B drug Mephedrone.
Insp Andy Croasdale said officers are continuing checks over Christmas.
He said: "We will be bringing our drugs dogs back to Bingley so if you come to the town in possession of illegal drugs, my warning is, expect to be caught and to face the detrimental consequences to your life from a conviction."