Riot police clash with demonstrators protesting against proposed pension reforms outside the Congress in Buenos Aires on December 18, 2017. Protesters angry at proposed pension and welfare reforms attacked police close to Argentina's congress building in Buenos Aires on Monday, the second protest in a week to turn violent. Activists lobbed stones, bottles and firecrackers at police as huge crowds demonstrated against pension reforms proposed by the center-right government of President Mauricio Macri. (Photo by Eitan Abramovich/AFP Photo)

St Louis County police officers arrest an anti-police demonstrator in Ferguson, Missouri August 10, 2015. Dozens of protesters were arrested on Monday afternoon after blocking rush-hour traffic on Interstate 70 a few miles (km) from Ferguson, Missouri, during demonstrations over the police shooting of an unarmed black man a year ago, according to a Reuters witness. (Photo by Lucas Jackson/Reuters)

A student protester throws a stone against a riot police vehicle during a demonstration to demand changes in the education system in Santiago, Chile, April 21, 2016. (Photo by Ivan Alvarado/Reuters)

A man drinks a Frucola as a policeman chases demonstrators during a protest against Chile's government in Santiago, Chile on December 4, 2019. (Photo by Goran Tomasevic/Reuters)

Demonstrators take part in a protest aimed at showing London's solidarity with the European Union following the recent EU referendum, inTrafalgar Square, central London, Britain June 28, 2016. (Photo by Dylan Martinez/Reuters)

A demonstrator kicks a riot police vehicle during an unauthorized march called by the Chilean student federations to protest against government's education reform, in Santiago, Chile July 5, 2016. (Photo by Ivan Alvarado/Reuters)

Demonstrators protest the shooting death of Alton Sterling near the headquarters of the Baton Rouge Police Department in Baton Rouge, Louisiana, U.S. July 9, 2016. (Photo by Jonathan Bachman/Reuters)

A woman and a girl in a school uniform run past a barricade of burning tires during a demonstration against high prices and fuel shortages, in Port-au-Prince, Haiti on October 21, 2021. (Photo by Ralph Tedy Erol/Reuters)