The Quang Binh online ring ran sport betting and a lottery, among other pursuits, said Quang Binh police who announced about the case Tuesday.

On Monday, over 120 police officers raided the residences of six people in Quang Binh and found four savings books worth over VND1.3 billion, around VND195 million in cash, a car, dozens of mobile phones, computers and documents related to gambling. All six have been arrested for investigation.

Further investigation showed over 30 people participated in the ring, having placed bets worth over VND1 trillion since July.

The online gambling ring in Hanoi saw 40-year-old mastermind Nguyen Tien Hung detained. Nine other ring members are also being probed, said police of the Ministry of Public Security on Tuesday.

An investigation revealed Hung had garnered capital to create the ring. He then hired a man named Duong Manh Tuan to form and manage intermediary websites, with servers placed outside Vietnam, for gamblers to indulge in sport betting and casino games, among others.

Tuan said he and some others were paid VND400-500 million a month to perform technical support and help gamblers create accounts and withdraw their money gained from gambling. Six others were put in charge of customer support, Tuan added.

The Hanoi ring, operational since February last year, hosted around 3,888 accounts and transacted over VND1 trillion in total, authorities said.

Gambling remains illegal in Vietnam outside its handful of casinos, and even there Vietnamese need to meet certain financial and other criteria to be allowed to partake.

Gambling and organizing related gaming activities carry fines of VND10-50 million ($430- 2,150) and jail terms of three to seven years.