Police and Immigration officers said they arrested 205 people in anti-triad and anti-crime operations in districts across Hong Kong.
The two operations - codenamed Flowingshade and Sahara - tackled a range of criminal activities, including drug trafficking, possessing offensive weapons, robbery, operating a gambling establishment, money laundering, and fraud.
Officers arrested 136 men and 69 women, aged between 14 and 82, in the crackdown, which ran between Thursday and Saturday.
In addition to the arrests, police seized suspected drugs, weapons, and gambling equipment.
Police said a number of suspects had already been charged.