More than 4,300 including around 1,100 from the mainland have been arrested in a joint campaign under the code name of "Thunderbolt 15" by Hong Kong Police Force from June 15 to Sept. 18, 2015.

Major crimes uncovered by police included drug dealing, gambling, prostitution and parallel trading in a three-month cross-border anti-triad operation in Hong Kong, Macao and Guangdong province from mid June to mid September, said Au Chin Chau, chief superintendent of the Hong Kong police’s Organized Crime and Triad Bureau. Confiscated goods worth around HKD 67 million.