HONG KONG, CHINA - NOVEMBER 18: Police arrest anti-government protesters at Hong Kong Polytechnic University on November 18, 2019 in Hong Kong, China. Anti-government protesters organized a general strike since Monday as demonstrations in Hong Kong stretched into its sixth month with demands for an independent inquiry into police brutality, the retraction of the word "riot" to describe the rallies, and genuine universal suffrage. (Photo by Laurel Chor/Getty Images)
HONG KONG, CHINA - NOVEMBER 18: Anti-government protesters stand during a lull in the middle of clashes with police at Hong Kong Polytechnic University on November 18, 2019 in Hong Kong, China. Anti-government protesters organized a general strike since Monday as demonstrations in Hong Kong stretched into its sixth month with demands for an independent inquiry into police brutality, the retraction of the word "riot" to describe the rallies, and genuine universal suffrage. (Photo by Laurel Chor/Getty Images)
HONG KONG, CHINA - NOVEMBER 18: A protester lights a petrol bomb in front of a fire on a pedestrian bridge during clashes with police at Hong Kong Polytechnic University on November 18, 2019 in Hong Kong, China. Anti-government protesters organized a general strike since Monday as demonstrations in Hong Kong stretched into its sixth month with demands for an independent inquiry into police brutality, the retraction of the word "riot" to describe the rallies, and genuine universal suffrage. (Photo by Laurel Chor/Getty Images)
aHONG KONG, CHINA - NOVEMBER 18: Anti-government protesters walk out of campus during clashes with police at Hong Kong Polytechnic University on November 18, 2019 in Hong Kong, China. Anti-government protesters organized a general strike since Monday as demonstrations in Hong Kong stretched into its sixth month with demands for an independent inquiry into police brutality, the retraction of the word "riot" to describe the rallies, and genuine universal suffrage. (Photo by Laurel Chor/Getty Images)
HONG KONG, CHINA - NOVEMBER 18: Anti-government protesters stand near a fire after police attempted to storm Hong Kong Polytechnic University on November 18, 2019 in Hong Kong, China. Anti-government protesters organized a general strike since Monday as demonstrations in Hong Kong stretched into its sixth month with demands for an independent inquiry into police brutality, the retraction of the word "riot" to describe the rallies, and genuine universal suffrage. (Photo by Laurel Chor/Getty Images)
aHONG KONG, CHINA - NOVEMBER 18: Anti-government protesters walk past a fire during clashes with police at Hong Kong Polytechnic University on November 18, 2019 in Hong Kong, China. Anti-government protesters organized a general strike since Monday as demonstrations in Hong Kong stretched into its sixth month with demands for an independent inquiry into police brutality, the retraction of the word "riot" to describe the rallies, and genuine universal suffrage. (Photo by Laurel Chor/Getty Images)
HONG KONG, CHINA - NOVEMBER 18: Police arrest anti-government protesters at Hong Kong Polytechnic University on November 18, 2019 in Hong Kong, China. Anti-government protesters organized a general strike since Monday as demonstrations in Hong Kong stretched into its sixth month with demands for an independent inquiry into police brutality, the retraction of the word "riot" to describe the rallies, and genuine universal suffrage. (Photo by Laurel Chor/Getty Images)
HONG KONG, CHINA - NOVEMBER 18: Anti-government protesters flee from the police at Hong Kong Polytechnic University’s campus on November 18, 2019 in Hong Kong, China. Anti-government protesters organized a general strike since Monday as demonstrations in Hong Kong stretched into its sixth month with demands for an independent inquiry into police brutality, the retraction of the word "riot" to describe the rallies, and genuine universal suffrage. (Photo by Laurel Chor/Getty Images)
HONG KONG, CHINA - NOVEMBER 18: Police arrest anti-government protesters at Hong Kong Polytechnic University on November 18, 2019 in Hong Kong, China. Anti-government protesters organized a general strike since Monday as demonstrations in Hong Kong stretched into its sixth month with demands for an independent inquiry into police brutality, the retraction of the word "riot" to describe the rallies, and genuine universal suffrage. (Photo by Laurel Chor/Getty Images)
HONG KONG, CHINA - NOVEMBER 18: Police chase anti-government protesters at Hong Kong Polytechnic University on November 18, 2019 in Hong Kong, China. Anti-government protesters organized a general strike since Monday as demonstrations in Hong Kong stretched into its sixth month with demands for an independent inquiry into police brutality, the retraction of the word "riot" to describe the rallies, and genuine universal suffrage. (Photo by Laurel Chor/Getty Images)
HONG KONG, CHINA - NOVEMBER 18: Police arrest anti-government protesters at Hong Kong Polytechnic University on November 18, 2019 in Hong Kong, China. Anti-government protesters organized a general strike since Monday as demonstrations in Hong Kong stretched into its sixth month with demands for an independent inquiry into police brutality, the retraction of the word "riot" to describe the rallies, and genuine universal suffrage. (Photo by Laurel Chor/Getty Images)
HONG KONG, CHINA - NOVEMBER 18: Police arrest anti-government protesters at Hong Kong Polytechnic University on November 18, 2019 in Hong Kong, China. Anti-government protesters organized a general strike since Monday as demonstrations in Hong Kong stretched into its sixth month with demands for an independent inquiry into police brutality, the retraction of the word "riot" to describe the rallies, and genuine universal suffrage. (Photo by Laurel Chor/Getty Images)
HONG KONG, CHINA - NOVEMBER 19: An anti-government protester attempts to escape Hong Kong Polytechnic University by going through a sewer on November 19, 2019 in Hong Kong, China. Anti-government protesters organized a general strike since Monday as demonstrations in Hong Kong stretched into its sixth month with demands for an independent inquiry into police brutality, the retraction of the word "riot" to describe the rallies, and genuine universal suffrage. (Photo by Laurel Chor/Getty Images)
HONG KONG, CHINA - NOVEMBER 19: Anti-government protesters wait to be seen by medics at Hong Kong Polytechnic University on November 19, 2019 in Hong Kong, China. Anti-government protesters organized a general strike since Monday as demonstrations in Hong Kong stretched into its sixth month with demands for an independent inquiry into police brutality, the retraction of the word "riot" to describe the rallies, and genuine universal suffrage. (Photo by Laurel Chor/Getty Images)
HONG KONG, CHINA - NOVEMBER 18: Anti-government protesters flee after clashing with police at Hong Kong Polytechnic University on November 18, 2019 in Hong Kong, China. Anti-government protesters organized a general strike since Monday as demonstrations in Hong Kong stretched into its sixth month with demands for an independent inquiry into police brutality, the retraction of the word "riot" to describe the rallies, and genuine universal suffrage. (Photo by Laurel Chor/Getty Images)
HONG KONG, CHINA - NOVEMBER 18: Police arrest anti-government protesters at Hong Kong Polytechnic University on November 18, 2019 in Hong Kong, China. Anti-government protesters organized a general strike since Monday as demonstrations in Hong Kong stretched into its sixth month with demands for an independent inquiry into police brutality, the retraction of the word "riot" to describe the rallies, and genuine universal suffrage. (Photo by Laurel Chor/Getty Images)