Eleven people, including separatist Chan Ho-tin, were arrested for possession of explosive material and offensive weapon as part of two separate crackdowns by police over late Thursday night and early Friday morning.

The arrests came a little more than two weeks after a similar arrest of four people in Tsuen Wan, in which police made a record explosive haul of triacetone triperoxide (TATP) and 10 self-made petrol bombs.

Of the 11 people arrested, eight were picked up at Haribest Industrial Building in Shatin, after police found explosive material, masks and helmets and offensive weapons, including bow and arrow at the scene. The unit where the arrests were made was believed to be one of the warehouses used by radical protesters who have carried out sustained attacks on police and government buildings since mid-June.

Soon after the arrest of the eight, about a hundred masked radicals converged near the building, attempting to keep police from leading away the suspects – seven men and a woman, aged between 24 and 31. Shortly after that, another group of masked radicals surrounded Shatin Police station. They demanded police free the suspects and vandalized the station by spraying black paint on the CCTV cameras mounted on the exterior of the police station and hurled eggs at the building.

The vandalism escalated when protesters quickly moved onto the Ma On Shan Police division after they learned that some suspects had been transferred there. They dismantled the metal gate of the building and started hurling bricks. The standoff lasted until around 3 am on Friday.

Three more people were arrested in Tin Shui Wai for possession of explosive material without license. These arrests were believed to in relation to a drive-by firework attack made on protesters outside Tin Shui Wai police station the day before. Several home-made smoke bombs were found at the scene.