HONG KONG - A 16-year-old teenager and a 52-year-old woman were arrested on Monday in Hong Kong on the suspicion of making or possessing explosives, police said.

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Chow Cheung-yau, superintendent of the Hong Kong police's Narcotics Bureau, said at a press conference that police had received a tip-off of persons purchasing raw chemical ingredients fit for manufacturing explosives from overseas via the internet since November last year.

Upon thorough investigation, police picked up the two people from two residential units in Wan Chai and seized four imitation firearms and a batch of chemicals stashed in the flats.

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Suryanto Chin-chiu, bomb disposal officer of the police's Explosive Ordnance Disposal Bureau, said those materials could be used to produce pyrotechnics or explosives and some chemicals were found to be in an unstable state. In case of an accident, it could well cause a fire or explosion, he said.