Ho Chi Minh City police on Monday arrested 28 people in a major Vietnam gambling ring. The illegal lottery is believed to have operated for more than a year. Police said the ring’s kingpin is 36-year-old Nguyen Ngoc Thang, who had served three convictions of mugging, robbery and causing public nuisance. Preliminary investigation found Thang organized so de, an illegal numbers game based on the state lottery, allowing players to bet any amount they want for payoffs up to 80 times the original wager. He employed dozens of agents across the city to receive bets in this illegal Vietnam gambling…