JAKARTA: Indonesian police ‌on Saturday arrested 321 foreign nationals, mainly from Vietnam, for alleged involvement in banned online gambling, ​officials said.

The suspects were arrested in an office building in Central Jakarta as authorities pursue crackdowns on online gambling — which is banned in the world’s largest Muslim-majority nation — and on international criminal syndicates.

Those arrested included 228 ‌people from Vietnam, ‌57 from China, 13 ​from ‌Myanmar, ⁠11 ​from Laos, ⁠five from Thailand and three from Cambodia, Wira Satya Triputra, director of the Indonesian police force’s crime investigation unit, said at a press conference.

The suspects have been running the online gambling operation for ⁠two months, Wira said.

Of ‌the 321 ‌people arrested, he said 275 ​were accused of violating ‌Indonesia’s criminal code on gambling, a ‌charge that carries a maximum sentence of nine years.

Wira said most of the foreigners were aware that they came to Indonesia ‌to run online gambling operations, adding that they largely targeted foreign ⁠customers.

An official with Interpol Indonesia, Untung Widyatmoko, told the press conference that there is a trend of online gambling operations moving from Cambodian cities to Indonesia.

It was the second round-up of a large group of foreigners in two days. On Friday, Indonesia’s immigration authorities arrested 210 foreign nationals allegedly involved ​in online investment scams ​on Batam island, around 20 km from Singapore.