Police said 22 Thais were also detained in the raid Tuesday night at 360 Bar on Koh Phangan, which is in the Gulf of Thailand off of Surat Thani.

Attendants and organizers of the party are facing charges of violating an emergency decree which was put in place last March to combat the coronavirus. Most of them have been released on bail, and only 28 are still being detained, said Police Col. Panya Nirattimanon, chief of the Koh Phangan provincial police station.

According to reports, police learned about the party when they saw tickets available for purchase online.

Among the foreigners arrested were 20 French citizens, 10 Americans and six Britons. All of the arrested were swabbed by local health authorities and found negative for Covid-19, Nirattimanon said.

"They are stranded tourists who can't leave Thailand due to Covid," Nirattimanon said. "They may think it is OK to gather in large groups and I think they may want to relax and have some fun."

Koh Phangan is a popular destination for backpackers due to its monthly full moon parties, which have been canceled.

All international arrivals are subject to a 14-day quarantine at a state-approved facility.

For months, Thailand reported few locally transmitted Covid cases thanks to its strict quarantine-on-arrival rules.