Revellers take part in the annual “Naval Battle” of Vallecas in Madrid, Spain July 19, 2015. The slogan for this year's water battle is “Get wet for Alfon, freedom for Alfon”, referring to Alfonso Fernandez Ortega, a Vallecas resident who was sentenced to four years in prison in June. The festival was started spontaneously in 1981 when some neighbours started to throw water at one another due to high temperatures during the Virgen del Carmen Festival. (Photo by Juan Medina/Reuters)

Revelers of the Holi Festival of Colors dance after throwing colored powders in the air in Madrid, Spain, Saturday, August 9, 2014. The festival is fashioned after the Hindu spring festival Holi, which is mainly celebrated in the north and east areas of India. (Photo by Daniel Ochoa de Olza/AP Photo)

A model waits backstage to present creations from the Fall-Winter 2021/2022 collection of the Georgiela Studio fashion brand during a young talents “EGO” fashion show on the last day of the 73rd Mercedes-Benz Fashion Week Madrid, in Madrid, Spain, 11 April 2021. The fashion event runs from 08 to 11 April. (Photo by Mariscal/EPA/EFE)

Chinese special policemen rank in a line of battle during an anti-terror drill at a training base of Chengdu Armed Police Headquarters on September 28, 2005 in Chengdu of Sichuan Province, China. (Photo by China Photos/Getty Images)

Members of the Ukrainian Interior Ministry's special battalion Kiev-1 rescue a hostage, who was detained by a mock terroist, during an anti-terror drill in Kiev, Ukraine, August 28, 2015. (Photo by Valentyn Ogirenko/Reuters)

Police officers clear the area near Borough market at London Bridge on June 3, 2017 in London, England. Police have responded to reports of a van hitting pedestrians on London Bridge in central London. (Photo by Dan Kitwood/Getty Images)

An Afghan policeman carries a wounded man at the site of a suicide attack in Kabul March 25, 2015. Six people were killed and more than 30 injured in the suicide bombing in the Afghan capital on Wednesday that struck close to the presidential palace in the heart of the city, the Interior Ministry said. The suicide bomber had been travelling in a vehicle packed with explosives and it was not immediately clear what the target of the attack had been. (Photo by Omar Sobhani/Reuters)

Military vehicles surround a wreckage of a trolleybus, in Volgograd, Russia, Monday, December 30, 2013. A bomb blast tore through a trolleybus in the city of Volgograd on Monday morning, killing at least 10 people a day after a suicide bombing that killed at least 17 at the city's main railway station. Volgograd is about 650 kilometers (400 miles) northeast of Sochi, where the Olympics are to be held. (Photo by Denis Tyrin/AP Photo)