Hong Kong police brief the media during a press conference in south China's Hong Kong, Oct. 16, 2019. The Hong Kong police said Wednesday they had seized explosives in several cases. The police said evidences have shown that rioters in the months-long violence were planning lethal attacks similar to terrorism. (Xinhua/Lu Hanxin)

HONG KONG, Oct. 16 -- The Hong Kong police said Wednesday they had seized explosives in several cases before and after one homemade bomb was detonated near a police vehicle on Sunday.

In a press conference, the police said evidences have shown that rioters in the months-long violence were planning lethal attacks similar to terrorism.

On Tuesday evening, two males, aged 17 and 23, were arrested after police found six petrol bombs and a suspected mobile phone-modified bomb detonator, said Raymond Chou, superintendent of Narcotics Bureau (Operations).

They faced charges including possession of explosives, unlawful assembly and possession of offensive weapons.

The arrests followed a remote-controlled homemade bomb was detonated near police officers who were clearing roadblocks set by rioters on Nathan Road, Kowloon, on Sunday. Police said it was the same explosive device used by terrorists all around the world.

Chou said three drones and projecting devices, as well as knifes and smoke shells, were also confiscated during the Tuesday swoop. The superintendent said using drones to project dangerous objects in densely populated places could cause heavy casualties.

The police have seized explosives or bomb-producing materials in several cases since July. On July 20, explosives, fire bombs and offensive weapons were found in a building in Tsuen Wan. On Aug. 1, materials for making explosives were seized inside a residential building in Tin Shui Wai.

Suryanto Chin-chiu, superintendent of the Explosive Ordnance Disposal Bureau, warned that homemade bombs are unstable and could explode during production and transportation, posing a big threat to public safety.