Macau saw a huge police sting on August 3 and 4 that harkened back to the triad days in the late 1990s when the enclave was still a Portuguese territory.

Bloomberg has reported that Macau police orchestrated a series of raids on casinos and hotels in a joint-operation with law enforcement officials in the mainland and Hong Kong after a spate of attacks on guests, some with fatal consequences.

Nevertheless, the mass crackdown is part of a wider operation known as “Thunderbolt,” which has seen police quiz over 1,300 people and detain 149.

Au Kam-sun, a Macau lawmaker, told Bloomberg:

“Crime comes inevitably with casinos… The police make a clean-up every now-and-then to keep the triads in check.”

That may be so, but the last few months have seen violent crime return to pre-handover days.  Bloomberg sums up the recent incidents:

Ng Man-sun, the largest shareholder of Amax Holdings Ltd. (959), was beaten in a restaurant at a casino operated by his company, the New York Times reported on June 28. The Macau New Century Hotel stopped accepting guests after the assault because “certain unidentified persons” had been staying there for a long time, according to the South China Morning Post on July 3.

Ng, also known by his nickname “Market Wai,” requested that eight of the nine directors of Amax’s board be removed and replaced by five new directors, according to a company statement to the Hong Kong stock exchange on July 16.

The attack on him was followed by the killing of a Chinese woman in a neighborhood near the Venetian Macau casino, and the murder of two men at the Grand Lapa Hotel, which is operated by Mandarin Oriental International Ltd. (MAND), according to the Hong Kong-based South China Morning Post.

The question now is whether the cleanup will be effective.