DENPASAR: An Indonesian court sentenced dozens of Indian nationals to prison on Wednesday for their involvement in an online gambling operation on the resort island of Bali.

Gambling is illegal in the Muslim-majority archipelago, with punishments extended to bookmakers, punters, those who promote gambling content online and gamblers themselves.

Police arrested 39 Indian nationals in February at two villas in separate locations on Bali and charged 35 of them.

The group entered Indonesia on tourist visas and had been promoting and managing transactions for an online gambling site since late last year, according to the police.

Presiding judge Putu Gde Novyartha found the men guilty in a Wednesday hearing, sentencing most of them to two years behind bars. Two were sentenced to two and a half years.

The judge also ordered “the defendants to be deported after serving the sentence... and once the sentence has been completed, the defendants are prohibited from visiting the territory of the Republic of Indonesia.”

The operation brought in up to eight billion rupiah (about $450,000) a month, police said.

Turnover linked to online gambling in Indonesia reached more than 280 trillion rupiah last year, official data showed, with more than 12 million of the country’s 287 million citizens estimated to be engaged in the illicit activity, most of them as gamblers.

Authorities said in May they would review the visa-free entry policy for nationals of Southeast Asian countries after a string of arrests of foreigners accused of running illegal gambling and scam operations.

Investigators have found that many of those allegedly involved in an illegal gambling center in Jakarta had entered Indonesia using visa waivers or applied for permits on arrival.