The force’s National Security Department said on Friday that some of the suspects were friends and had allegedly gathered near the scene of the Tai Po fire wearing clothing typically associated with anti-government activists during the 2019 social unrest.
Officers raided the factory space on Thursday night and seized several suspected explosive devices, at least five converted air guns, five military knives and a long sword, police said, adding that a 3D printer was also discovered at the scene.
Six men, aged 20 to 25, were apprehended at the scene, while three others, aged 20 to 22, were arrested subsequently in Tuen Mun and Yau Ma Tei.
The suspects were still being held for questioning, the force said.
The raid follows a nearly two-year investigation after it received tip-offs about the “illegal drilling” or military-style training activity at the factory premises.
