Some of London's telephone operators and engineers, trying out their gas masks at the anti-gas civilian training centre in Gloucester, where they were taught how to deal with gas attacks. (Photo by Harry Todd/Fox Photos/Getty Images). 13th February 1937

People lay flowers for and mourn the anti-government protesters who were killed in the past weeks’ clashes with riot police.

Members of the South Korean Special Weapons and Tactics team exhibit their skill during anti-terrorism exercises at a training camp on May 30, 2005 in Seoul, South Korea. (Photo by Chung Sung Jun/Getty Images)

A protester holds a poster displaying the message “Get away UK” during an anti-British demonstration in the Iranian capital that resulted in a break in at the British Embassy on November 29, 2011 in Tehran, Iran. (Photo by FarsNews/Getty Images)

A Kashmiri girl holds her brother in the doorway of their home while watching protesters shout pro-freedom and anti-Indian slogans during mourning and protests held in downtown Srinagar on August 22, 2016, following the killing of teenager Irfan Ahmed by security forces. Teenager Irfan Ahmed was killed after he was hit in the chest by a teargas canister fired by Indian security forces to quell pro-freedom protests in the Kashmiri capital on August 21. More than 60 civilians have been killed in clashes between protesters and security forces, and thousands more injured in the worst violence to hit the Himalayan region since 201. Indian-administered Kashmir has been in the grip of almost daily anti-India protests and rolling curfews sparked by the killing on July 8 of a popular rebel leader, Burhan Wani, in a gunfight with government forces. (Photo by Tauseef Mustafa/AFP Photo)

Anti-balaka militia originally sprang up to protect the Christian population of the Central African Republic, but now stand accused of human rights abuses themselves. Last month, the African Union branded militia targeting Muslims in Central African Republic as “terrorists” and said they would be treated as enemy combatants, a day after killing a Congolese peacekeeper and amid deepening international frustration at continuing violence in the impoverished and landlocked country. Photo: A female member of the anti-balaka, a Christian militia, patrols with other militiamen outside village of Zawa April 8, 2014. (Photo by Goran Tomasevic/Reuters)

People take part in the Million Mask March anti-establishment protest at Trafalgar Square in London on November 5, 2020, on the first day of a four week national lockdown for England. (Photo by Aaron Chown/PA Images via Getty Images)

A police officer tries to prevent an anti-government protester from pulling the hair of a woman who is part of group that appeared to show their support for the government during a march of healthcare workers critical of the government, in La Paz, Bolivia, on July 21, 2022. (Photo by Juan Karita/AP Photo)