The first arrests have been made in Hong Kong after a new national security law for the territory came into effect.
Pepper spray has been used on protesters marking 23 years since British rule came to an end.
China's new legislation punishes secession, subversion and terrorism with sentences of up to life in prison.
For the first time authorities had banned pro-democracy marches on the July 1st anniversary of sovereignty being handed back to Beijing.
Former UK diplomat Charles Parton says Britain will need to respond.
IN: "We have...
OUT: ...reaction."
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