Pro-democracy activists cheer themselves up in Hong Kong on July 1, 2020, before they march in protest against Beijing's enactment of a controversial national security law for the former British colony. (Kyodo)

HONG KONG - Hong Kong police said Wednesday they have made the first arrest under a new sweeping national security law that went into force late Tuesday.

The police arrested a man for allegedly holding a flag advocating the territory's independence in violation of the law, they said on Twitter, with photos purportedly showing the flag spread on the floor.

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