Police, bystanders and soldiers aid a fallen soldier at the War Memorial as police respond to an apparent terrorist attack on October 22, 2014 in Ottawa, Canada. A gunman is believed to have shot a soldier as he was standing guard at the National War Memorial in Ottawa. It is believed police then chased the man into the main parliament building at Parliament Hill, where more shots were fired. (Photo by Wayne Cuddington/Postmedia/Barcroft Media/ABACAPress)

Demonstrators throw fire bombs to riot police during violent protests in central Athens February 12, 2012. (Photo by Milos Bicanski/Getty Images)

A reveller dances next to a police officer at Notting Hill Carnival in London, Britain on August 28, 2022. (Photo by Henry Nicholls/Reuters)

A protestor confronts police and National Guard troops near the Wauwatosa City Hal on October 09, 2020 in Wauwatosa, Wisconsin. The city has faced three days of demonstrations, prompting a 7 PM curfew, after District Attorney John Chisholm refused to press charges against Wauwatosa Police Officer Joseph Mensah for the Feb. 2 fatal shooting of 17-year-old Alvin Cole. (Photo by Scott Olson/Getty Images)

Protesters run for cover after riot police fired tear gas towards the bridge they were climbing down to the road below, to escape from Hong Kong Polytechnic University campus and from police, in Hung Hom district in Hong Kong on November 18, 2019. Dozens of Hong Kong protesters escaped a besieged university campus on November 18 by lowering themselves on a rope from a footbridge to a highway, AFP video showed. Once on the road they were seen being picked up by waiting motorcyclists. (Photo by Anthony Wallace/AFP Photo)

A police dog licks its face after receiving food during the dog festival, as part of celebrations of Tihar at Nepal Police Academy in Kathmandu October 22, 2014. Hindus all over Nepal are celebrating the Tihar festival, also called Diwali, during which they worship cows, which are considered a maternal figure, and other animals. Also known as the festival of lights, devotees also worship the goddess of wealth Laxmi by illuminating and decorating their homes using garlands, oil lamps, candles and colourful light bulbs. (Photo by Navesh Chitrakar/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)

A demonstrator throw a firebomb during clashes with Turkish riot police officers in Istanbul, Turkey, Friday, May 1, 2015. The government assigned 30,000 police officers backed by helicopters as workers and demonstrators determined to defy a government ban, tried to march to iconic Taksim Square, where 35 people were killed during May Day celebration in 1977. (Photo by Emrah Gurel/AP Photo)