Huge crowds of demonstrators dressed in white filled the streets of Hong Kong, marching against a proposed extradition law.
They fear it could allow the Chinese authorities to target political opponents in the territory.
The controversial extradition bill would allow suspected criminals to be sent to mainland China for trial.
The government says the bill has built-in protections.
Supporters say safeguards are in place to prevent anyone facing religious or political persecution from being extradited to mainland China.
But critics say those in the former British colony would be exposed to China’s deeply flawed justice system, and it would lead to further erosion of the city’s judicial independence.