About 200 officials raided a pub on Pattaya's Walking Street early Sunday morning and found traces of drug abuse among the customers.
The horde of police, local government and narcotics officials gathered near Bali Hai Pier before launching the raid at 3am, storming into Club Panda. There were about 400 customers inside enjoying the music, many of them dancing.
Staff were ordered to turn off the music and turn on the lights, and men and women split into separate groups.
Urine tests on customers found traces of drugs in five people, one a foreigner. Officials said they had probably used ketamine. Charges were pending.