Police cracked down an illegal gambling site allegedly controlled by triads. Photo: Google Map/ Wiki Commons

Police arrested 20 people in an illegal gambling den in a cooked food center in an Aberdeen market late on Tuesday evening in the Southern District of Hong Kong Island.

At 11:10pm, 11 men and three women, aged between 20 and 60, were arrested on suspicion of gambling outside of registered venues at Yue Kwong Road Market Cooked Food Center, Apple Daily reported. In Hong Kong, gambling is only allowed in registered venues such as mahjong parlors and branches of the Hong Kong Jockey Club.

Six other men were arrested for allegedly operating the gambling den, which had been open for a month.

After business hours, the food center became a gambling den, offering mainly Chinese poker and three kings, police said.

The gambling den was hidden behind canvas, while guards used walkie-talkies to communicate with the croupier at the table inside, Oriental Daily reported. Some of the people arrested had triad society backgrounds, the police said.

Officers from the special duties, anti-triad and crime units conducted the raid in a joint operation. A gambling table, HK$5,000 (US$643) in cash, a deck of cards and three sets of walkie-talkies were seized.