Hong Kong national security police have arrested five more people including at least one teenager over an alleged plan to launch a city-wide bombing campaign targeting transport infrastructure and court buildings, the force said Monday.

One female and four males between the ages of 15 to 37 were detained on suspicion of “conspiring to organise terrorist activities” by manufacturing explosives which they intended to use.

Photo: Kelly Ho/HKFP.

Nine members of an alleged “revolutionary” group called “Returning Valiant,” including six secondary school students, were arrested on the same charges early last week.

National security officers searched the homes and workplaces of the five detained on Monday and seized evidence, police said. They are being detained for investigation.

They were arrested on suspicion of violating Article 24 of the Beijing-imposed national security law, which bans the organising and planning of “terrorist acts,” broadly defined to include sabotaging public transport and other infrastructure.

Offences under this article are punishable by between three and 10 years unless they result in death, serious injury or significant damage.

“The police investigation is still ongoing and the force does not rule out further arrests,” a statement said.

Items seized by the police. Photo: Hong Kong Police, via video screenshot.

In last week’s operation police raided a hostel in Tsim Sha Tsui and said they found a small quantity of explosives, raw materials for manufacturing bombs, and laboratory equipment for making triacetone triperoxide (TATP), a highly unstable explosive prone to unintended detonation.

Officers also found cash, SIM cards, air guns and operational manuals. Detectives said they believe the group was planning bomb attacks on public facilities across the city, including cross-harbour tunnels, railways and court buildings. The police said the group also planned to put bombs in rubbish bins, according to an operational manual.

Police did not confirm whether the arrests on Monday also involved members of Returning Valiant.

A member of the group was among people arrested in May for “subverting state power” after paraphernalia promoting Hong Kong independence was allegedly found in their homes.

Rhoda Kwan

Rhoda Kwan is HKFP's Assistant Editor. She has previously written for TimeOut Hong Kong and worked at Meanjin, a literary journal. She holds a double bachelor’s degree in Law and Literature from the University of Hong Kong.