Police officers arrested three men on multiple drugs offences in a Monday morning raid at two locations in the autonomous Chinese territory on the western side of the Pearl River Delta.
The trio were arrested for allegedly trafficking and consuming drugs, and possession of tools to take the illegal substances.
Officers arrested a 41-year-old Filipino, surnamed Batanhan, and seized 2.2 grams of ketamine in a casino at 1am in the Nape area, Macao Daily News reported. He also admitted he had a methamphetamine habit.
Shortly afterward, police seized five packets of ketamine with a combined weight of 5.9 grams, 13.7 grams of cannabis and arrested two men, 36 and 37, from the West African nation of Mali.
The pair, surnamed Toure and Samate, were arrested in a washroom near the Camoes Grotto tourist spot in the former Portuguese colony whose sovereignty was transferred back to China in 1999.
Police said the suspects had been trafficking drugs for at least six months, mainly providing supplies for nightclubs.