The Police Force’s National Security Department has arrested nine men on suspicion of committing "unlawful drilling" offences under the Safeguarding National Security Ordinance.

The arrestees, aged between 20 and 25, were netted in an operation mounted recently in various districts.

Investigations found that a syndicate conducted unlawful drilling inside a unit of an industrial building in Kowloon. The training encompassed firearm drills, use of tactical knives and combat techniques.

Offensive weapons were seized in the operation.