Police shut down two illegal gambling dens and arrested 22 people at apartments in North Point during raids early Wednesday as a major operation against organized crime activities began to wind down.

About HK$25,000 (US$3,184) of cash was seized at the casinos, which are believed to have been operated by a triad group. The police also confiscated four electronic game machines, some card readers  and two accounting books, as well as game cards.

Two men with the surnames Tsang and Yip, respectively aged 28 and 36, were arrested in the apartments at 73 Chun Yeung Street and 338 King’s Road, which are both in North Point. Twenty other people aged between 25 and 56 were also held, including 16 for alleged gambling offences. Two Filipinas with Hong Kong identity cards were arrested.

The raids followed a series of crackdowns by police and immigration officials on Tuesday in Yau Ma Tei that led to the arrests of 26 women from mainland China on vice charges. Police say the women were in brothels and hotel rooms on Nathan Road, Temple Street, Portland Street, Reclamation Street, Shanghai Street and Jordan Road.

Both operations were part of Thunderbolt 18, a campaign launched in June in conjunction with police in Macau and Guangdong province that targeted organised crime syndicates. Several thousand arrests have been made for illegal drugs, gambling and prostitution.