A police officer displays weapons and other contraband goods during a news conference on operation "Thunderbolt 15" on Wednesday. [Photo by Roy Liu / China Daily]

Police have apprehended more than 19,000 suspects in a three-month cross-border anti-triad operation in Hong Kong, Macao and Guangdong province.

Law enforcement officers from the three places are expected to take inter-force cooperation to new heights following the success of the longest joint operation of its kind.

In Hong Kong, a total of 4,343 people — including 1,177 from the mainland — were rounded up after more than 7,500 places including vice dens, gambling venues and residential flats were searched. Officers confiscated about HK$102 million in cash, HK$67 million worth of illegal drugs, weapons, pirated DVDs and contraband cigarettes.

Major crimes uncovered by police included drug dealing, gambling, prostitution and parallel trading, according to Au Chin-chau, chief superintendent of the Hong Kong police’s Organized Crime and Triad Bureau.

Illegal loan businesses were found to be a new income source of local triads, said Au.

Five major undercover actions were carried out during the operation from June to September, he said.

The arrests were mainly members of triads from Hong Kong and the mainland — including some high-ranking ones, Au revealed.

"The message we want to send out to the public is that police have ‘zero tolerance’ for organized crimes and any other illegal activities," Au said.

Through "intelligence-led" operations, the regular joint action, codenamed "Thunderbolt 15", is marshaled to combat organized and serious crime. It also tackles triad activities — particularly those involving cases of serious violence, drug dealing and vice syndicates.

On the other side of the border, mainland police arrested 11,339 suspects — along with 31,651 drug addicts — in Guangdong province during the operation.

A new trend showed triads from Hong Kong and Macao change tactics and make forays into the mainland. This is to seek cooperation and plan criminal activities, a Guangdong police spokesman explained.

He also pledged that they will launch another joint operation soon with Hong Kong police, who are confronting the current surge in phone scams.

According to Guangdong police, 90 percent of these cases originate in Maoming city, Guangdong.

Meanwhile, a total of 3,977 people were arrested in Macao.

Contact the writers through luisliu@chinadailyhk.com