Two teenage students were among 98 men and 37 women arrested in gambling dens raided in a two-day Hong Kong police operation.

The police’s anti-triad squad and officers from various police districts raided 63 game centers and illicit gambling establishments in the city on Thursday and Friday, Sing Tao Daily reported.

Among the 135 people arrested, two gamblers were 15-year-old students.

Fifteen citizens from India, Pakistan, Thailand, Bangladesh and the Philippines were arrested, five of whom were asylum seekers. Another seven mainland Chinese citizens holding two-way permits were arrested for working in the gambling establishments, where reportedly they could earn around HK$700 (US$89) to HK$1000 daily.

Officers confiscated 153 arcade machines, including fishing games and slot machines, together with HK$650,000 cash, 15 value-added machines, 11 card reading machines and 300 gaming cards.

Superintendent Chung Lai-yee from the Organised Crime and Triad Bureau said they noticed illegal gambling activities had increased in the city since March, with crime syndicates renting old buildings and factory premises to turn them into gambling establishments, Oriental Daily reported.

The establishments, which are believed to have been under the control of four or five triad organizations, operated 24 hours a day.

Two game centers, both with legal licenses located in Kowloon’s Sham Shui Po and Yau Ma Tie were involved in the police raids. It is understood that after business hours, the game centers would continue to operate, while only allowing entry to regular gamblers.

The gamblers could cash in their winnings if they won, which is illegal in Hong Kong. Sources say that some establishments also provided illegal drugs like cocaine and marijuana to gamblers.