A total of 137 clubgoers tested positive for drugs in a raid on an entertainment venue in Pathum Thani early on Sunday.
The 1.45am raid on MEM Exclusive Club, or MEM Pub, in Lam Luk Ka district, was led by officials. No police took part in the operation.
About 300 people were in the pub at the time of the raid. Many of them were under 20 years old and five did not carry an identification card.
Urine tests produced 137 positive results among the patrons.
The pub owner and several managers were arrested.
Officials said the raid followed complaints filed by local residents that the pub had illegally allowed youngsters under 20 years of age inside and the place had been used for selling and using drugs. Moreover, the complaints said, the pub was sometimes open until 6am.