A demonstrator confronts riot police during a rally in defense of the nationalization of lithium reserves in the country, in Santiago, Chile on January 29, 2018. (Photo by Pablo Sanhueza/Reuters)
A riot policeman fires into the air during clashes with opposition supporters at a rally demanding a referendum to remove President Nicolas Maduro in Caracas, Venezuela, May 11, 2016. (Photo by Carlos Garcia Rawlins/Reuters)
Wounded people walk after clashes with riot police in central Kiev February 18, 2014. Ukrainian riot police advanced on the heart of 12-week-old protests against President Viktor Yanukovich on Tuesday and security forces set a deadline to end disturbances after at least five protesters were reported killed in a day of clashes. (Photo by Vlad Sode/Reuters)
Riot policemen launch tears gas canisters during clashes with coca growers from Yungas in La Paz, Bolivia February 21, 2017. (Photo by David Mercado/Reuters)
A British Army Rolls Royce armoured car outside the Royal Ulster Constabulary police station on York Street in Belfast following riots after an Orange Order parade. (Photo by Fox Photos/Getty Images). 20th June 1935
A demonstrator holds a rose and shouts slogans in front of a riot policeman during an unauthorized march called by secondary students to protest against government education reforms in Valparaiso, Chile, May 26, 2016. (Photo by Rodrigo Garrido/Reuters)