A woman waits at a polio immunisation health centre, in Maiduguri, Borno State, Nigeria, August 29, 2016. Nigeria's military has liberated large swathes of land from Boko Haram but a ride with an army convoy, all guns firing for fear of ambush, shows how far the northeast is from normality after a brutal Islamist insurgency that has displaced millions. (Photo by Afolabi Sotunde/Reuters)

Members of the Compagnie 1602 take part in a procession in Geneva December 14, 2014. The annual procession of the Fete de l'Escalade has been held since 1926 and commemorates local resistance to the December 11, 1602 surprise attack by the troops of the Duke of Savoy. A popular symbol of the resistance is the figure of Mere Royaume pouring hot soup from her caldron onto the soldiers. A chocolate replica of the cauldron is widely available during the three-day celebrations. This year marks also the 200-year anniversary of the entry of the Canton of Geneva in the Swiss Confederation. (Photo by Pierre Albouy/Reuters)

Gas-masked men of the British Machine Gun Corps with a Vickers machine gun during the first battle of the Somme, 1916. (Photo by General Photographic Agency/Getty Images)

Ukrainian Serviceman Oleksii Hodzenko, aka Godzilla, was a civilian journalist. His father, Sergeant chief Dmytro "Godzilla" Godzenko was killed on March 31, 2016 at 6 a.m. in a mortar attack near the village of Zaitsevo near Horlivka in the Donetsk region. Since then Godzilla "junior" has joined the army, at a frontline position held by Ukraine's 503rd Detached Marine Battalion on February 7, 2022 near Verkhnotoretske, Ukraine. Regional tensions remain high as Russia continues to amass soldiers and military equipment along its border with Ukraine, where large swaths of the Luhansk and Donetsk regions are held by Russian-backed separatists. Russia has also moved roughly 30,000 troops into Belarus, which borders Ukraine to the north. American and European officials say they do not whether Russian President Vladimir Putin has made a decision to invade Ukraine, but have issued a series of warnings about the country's assertive military posture. (Photo by Gaelle Girbes/Getty Images)

A fireman from the London Fire Brigade, wearing a smoke helmet. (Photo by Topical Press Agency/Getty Images). Circa 1908

Russia-backed separatists stand at the site of the crashed Malaysia Airlines Flight 17 plane, near the village of Hrabove, eastern Ukraine, Thursday, July 16, 2015. The fighters said they have arrived to protect the media and make sure the MH17 crash site is clear of ammunition and mines. A year since a Malaysia Airlines Boeing 777 was blown out of the sky over war-ravaged eastern Ukraine, killing 298 people, there has been little official word of progress in determining what brought down Flight MH17. (Photo by Antoine E. R. Delaunay/AP Photo)

Comandos de Salvamento rescuers Maria Martinez (L) and Ana Chichilla attend to a wounded homeless man in San Salvador, El Salvador July 16, 2016. The man was attacked with a machete by suspected gang members. In 2015, El Salvador registered a record 103 homicides per 100,000 habitants, making it one of the most dangerous countries in the world outside a war zone. But for many young people who have few chances to distance themselves from rivalries between so-called maras in their schools and neighbourhoods, a civil-society organisation called the Comandos de Salvamento, or Rescue Corps, has been a refuge. (Photo by Jose Cabezas/Reuters)