Demonstrators stand behind barricades, surrounded by tear gas, during a protest in Tsuen Wan, in Hong Kong, China, August 25, 2019.

A demonstrator holds a flag a during a protest in Hong Kong, China, August 24, 2019.

Riot police officer approaches a demonstrator during a protest in Tsuen Wan, in Hong Kong, China, August 25, 2019. Image used for illustrative purpose.

Demonstrators stand during a protest in Tsuen Wan, in Hong Kong, China August 25, 2019.

A riot police shoots a tear gas canister during a protest in Tsuen Wan, in Hong Kong, China, August 25, 2019.

Demonstrators use a slingshot as they clash with riot police during a protest in Tsuen Wan, in Hong Kong, China, August 25, 2019.

A demonstrator uses an umbrella to take cover during a protest in Tsuen Wan, in Hong Kong, China August 25, 2019.

Demonstrators collect bricks as they clash with riot police during a protest in Hong Kong, China, August 25, 2019.

Riot police use water cannon on demonstrator as they clash during a protest in Tsuen Wan, in Hong Kong, China, August 25, 2019.

Riot police detain a demonstrator during a protest in Tsuen Wan, in Hong Kong, China August 25, 2019.

Riot police clash with demonstrators during a protest in Hong Kong, China, August 24, 2019.

An anti-extradition bill protester throws eggs as protesters clash with riot police during a rally to demand democracy and political reforms, at Tsuen Wan, in Hong Kong, China August 25, 2019.

A demonstrator uses a slingshot during a protest in Tsuen Wan, in Hong Kong, China August 25, 2019.

A demonstrator stands on a traffic light during a protest in Hong Kong, China, August 25, 2019.

Police clash with anti-extradition bill protesters after a protest, at Tsuen Wan, in Hong Kong, China August 25, 2019.

Police officers clash with demonstrators during a protest in Hong Kong, China, August 25, 2019.

An anti-extradition bill protester mops the ground with dishwashing liquid to try to slip riot police during a protest to demand democracy and political reforms, at Tsuen Wan, in Hong Kong, China August 25, 2019.

Fire is seen after anti-extradition bill protesters threw molotov cocktails during clash with riot police during a protest to demand democracy and political reforms, at Tsuen Wan, in Hong Kong, China August 25, 2019.

An anti-extradition bill protester raises his tennis racket while clash with riot police during a protest to demand democracy and political reforms, at Tsuen Wan, in Hong Kong, China August 25, 2019.

A general view shows riot police shooting a tear gas canister as demonstrators take cover behind barricades during a protest in Tsuen Wan, in Hong Kong, China August 25, 2019.

Police advance during clashes with anti-extradition bill protesters in Hong Kong, China August 25, 2019. Picture taken August 25, 2019. =

An anti-extradition bill protester holds a flag as he attends a march protest at Kwai Chung Sports Ground in Hong Kong, China, August 25, 2019.

Demonstrators react to tear gas as they clash with riot police during anti-extradition protest in Hong Kong, China August 25, 2019.

Riot police fire tear gas to disperse anti-extradition bill protesters after a march to demand democracy and political reforms, at Wong Tai Sin, Hong Kong, China August 24, 2019.

A demonstrator stands in front of riot police during a protest in Tsuen Wan, in Hong Kong, China August 25, 2019.

A man points a flashlight towards riot police (unseen) during a protest in Wong Tai Sin in Hong Kong, China, August 24, 2019. Photo taken on August 24, 2019.

Riot police detain a demonstrator as they clash during a protest in Hong Kong, China, August 24, 2019.