Kocha Olarn, CNN

Thai police arrested 89 foreigners on suspicion of breaching coronavirus restrictions after raiding a party at a bar on a popular resort island in southern Thailand, police told CNN on January 29.

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."

The maximum penalty for violating the emergency decree is two years' imprisonment and/or a fine of up to 40,000 baht ($1,330). The organizers are facing an additional charge of serving alcohol as this area in Thailand is banned from serving alcohol inside restaurants under the emergency law.

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

Thailand closed its borders to international tourism in April 2020. For the most part, the country remains off limits for all but returning nationals and permanent residents, though foreign tourists can apply for a Special Tourist Visa (STV).

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.

However, a spike in cases in December following an outbreak at a shrimp market in Samut Sakhon, a province southwest of Bangkok, led the government to reintroduce various measures aimed at containing the virus.