Children guarded by Hungarian police play on the ground after being detained along with other migrants who illegally crossed from Serbia to Hungary near the village of Asotthalom, Hungary, September 16, 2015. (Photo by Dado Ruvic/Reuters)

A fellow officer comes to the aid of injured patrolman C.V. Satt, who was pelted with rocks and beer bottles during a clash between police and relief demonstrators in Denver September 23, 1935. (Photo by Henry G. Eisenhand/AP Photo)

A woman on a bicycle rides past the remains of an Audi sedan set afire by an arsonist recently in Zehlendorf district in a street where two more cars were torched on August 23, 2011 in Berlin, Germany. Police have so far made no arrests in a series of arson attacks that have destroyed at least 70 cars within the last week and show no signs of abating. In recent years several hundred cars have been torched annually and police suspect left-wing radicals. The recent series of attacks, averaging about 10 a day, has been particularly severe. (Photo by Sean Gallup/Getty Images)

Indian policemen carry the body of one of their colleagues killed in a rebel attack in the town of Dinanagar, in the northern state of Punjab, India, Monday, July 27, 2015. Indian forces fought an extended gunbattle Monday with militants who attacked a moving bus and stormed into a police station in a northern town bordering Pakistan. (Photo by Channi Anand/AP Photo)

A protester holding a torch runs past police (not pictured) trying to stop the protesters from marching in a rally organised by a 30-party alliance led by a hardline faction of former Maoist rebels, who are protesting against the draft of the new constitution, in Kathmandu August 15, 2015. The group says that the draft is not inclusive and does not protect the rights of the marginalised and underprivileged groups in the country. (Photo by Navesh Chitrakar/Reuters)

Participants approach a law enforcement officer with open arms during an opposition demonstration to protest against police violence and to reject the presidential election results near the Government House in Independence Square in Minsk, Belarus on August 14, 2020. (Photo by Vasily Fedosenko/Reuters)

Alan Swinney points a gun during clashes between groups like Proud Boys and Patriot Prayer, and protesters against police brutality and racial injustice in Portland, Oregon, U.S., August 22, 2020. (Photo by Maranie Staab/Reuters)

A couple kiss in front of a barricade set by demonstrators during clashes with police following a protest condemning the arrest of rap singer Pablo Hasél in Barcelona, Spain, Thursday, February 18, 2021. Protests over the imprisonment of a rapper convicted for insulting the Spanish monarchy and praising terrorist violence have morphed for the third night in a row into rioting. Pablo Hasél began this week to serve a 9-month sentence in a northeastern prison. (Photo by Emilio Morenatti/AP Photo)