Violent clashes between police and demonstrators broke out in Hong Kong on Sunday at a rally against China's treatment of its Uighur minority.
China has been accused of a mass crackdown against Uighurs and other predominantly Muslim minorities in its Xinjiang region, with reports of millions being held in heavily secured, prison-like camps.
But Beijing claims the country holds no political prisoners and insists the centres are for vocational training and to save them from religious radicalism.
Police used pepper spray on protesters who threw missiles at them as what started out as a peaceful rally descended into chaos.
The thousands of demonstrators who had gathered in the city's Edinburgh Place earlier in the day waved flags in support of independence for Hong Kong.
The territory has been in the grip of a pro-democracy movement, which began over an extradition bill seen by opponents as part of increased meddling from Beijing, for the past six months.
Despite the legislation being shelved, protests have morphed to take on wider issues.