Gummies allegedly containing substances derived from cannabis are under police investigation after nearly 10 people who ate them were taken to hospital recently in Tokyo, investigative sources said Wednesday.

Five people aged from their teens to their 50s were taken ill on Nov. 4 after eating the gummies, which were handed out by a man during a festival held at a park in western Tokyo, the sources said, adding that their symptoms included vomiting.

The man admitted to handing out the gummies at the festival, and was quoted by the sources as telling the police in voluntary questioning, "Since I ate some myself and felt good afterwards, I wanted everyone else to eat them."

The gummies the man handed out were a product manufactured by a company based in Osaka City in western Japan. The ingredients printed on a label included HHCH, or hexahydrocannabihexol, according to the Tokyo metropolitan and Osaka governments.

HHCH is a synthetic substance with a structure similar to tetrahydrocannabinol, or THC, a constituent of cannabis, and can cause effects such as hallucinations and memory impairment.

While THC is banned in Japan, HHCH is not, according to the health ministry.

The man who handed out the gummies was identified to police by organizer of the festival, the sources said.

In another case, four people in their 20s were taken to hospital on Nov. 3 after feeling sick at Oshiage Station, a railway station in Tokyo's Sumida Ward, police said.

One of them was quoted by police as saying that they felt ill after "eating a cannabis gummy before riding the train."

Although the two cases occurred on consecutive days, investigators suspect they are unrelated, police said.

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