At least two of the three men arrested at the weekend over the city’s biggest bomb plot are members of different pro-independence groups, suggesting there could have been collaboration across the movement, it emerged on Sunday.
Both groups have denied knowledge of the explosives found at an industrial building in Tsuen Wan, with one of them labelling the arrest as political suppression, saying their organisation never had any plans to use bombs.
A 27-year-old man, surnamed Lo, was arrested on Friday night at Lung Shing Factory Building in Texaco Road, following a police raid on the building that led to the discovery of 10 petrol bombs and about 2kg of the powerful explosive triacetone triperoxide (TATP).
TATP has been used in deadly attacks all around the world, such as the London bombings of July 7, 2005, in which 52 people were killed and more than 700 injured. Even a small amount of the explosive is poweful enough to blow a car to bits, and can be dangerous to anyone handling it because of its instability.
The police conducted controlled explosions to dispose of the extremely powerful and highly unstable explosives onsite.
While Lo was a member of Hong Kong National Front, one of the two 25-year-olds arrested on Saturday night, surnamed Tang, belonged to Hong Kong Independence Union.
Tang was arrested at his Fanling home while the third suspect, surnamed Hau, was arrested at his residence in Tsuen Wan.
Wayne Chan Ka-kui, convenor of the union, confirmed on Sunday that Tang was one of its members and was still being held by police to assist in investigations.
“We never had any plans to resort to explosives. I would say it is a political suppression,” Chan said.
The group also issued a post on social media, saying: “We would not be scared by even more arrests.”
A police spokesman said the three, who were still detained as of Sunday evening, were arrested for possession of explosives without a licence.
The pair arrested on Saturday night were understood to be closely associated with Lo, who reportedly rented the unit.
In addition to the explosives, police seized knives, catapults, helmets, face masks and goggles. Other items uncovered were Hong Kong National Front T-shirts, leaflets bearing the message “no extradition to China” and pamphlets promoting the June 9 extradition march.
A police source said detectives were still investigating the source of the explosives and what they were intended for. Superintendent Alick McWhirter of the Explosive Ordnance Disposal unit said: "I think, without a doubt, this is the largest seizure we have ever come across in Hong Kong."
Senior Superintendent Steve Li Kwai-wah, of the Organised Crime and Triad Bureau, said on Saturday that the industrial unit had been rented out for a few months and they would investigate whether the seizure was related to the recent extradition bill march.
The Hong Kong Independence Union was founded last year, while Hong Kong National Front, which Leung said had dozens of members, was founded in 2015.
If convicted, those arrested in connection to the plot could face up to 20 years in jail under the law.