Preliminary investigations showed that online transactions, worth more than 3 billion CNY (435.51 million USD), were carried out through different activities like sports betting and illegal lottery.
Police confiscated nearly 2,000 smartphones, 530 computers, bank cards, cash and other relevant objects and documents at the site.
The ring members, aged from 18-24, came to Vietnam as tourists and received around 3,000 CNY (435 USD) each month.
The case is under further investigation.
Vietnam is considered to have one of the strictest anti-gambling laws in the world, with most forms of gambling being illegal.