A protesting student runs past a burning bus off campus outside the University of the Witwatersrand in Johannesburg, South Africa on Monday, October 10, 2016. Tear gas and water cannon were fired as hundreds of students protested at the university amid a bitter national dispute with university managers and the government over demonstrators' demands for free education, forcing student into the neighbouring city streets. (Photo by AP Photo)

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)

Protesters are detained by police in central Istanbul, Saturday, June 26, 2021. Police used tear gas and rubber bullets to disperse the crowds and detained dozens of LGTBI activists as hundreds defied a ban and tried to stage a gay pride event. (Photo by Emrah Gurel/AP Photo)

This handout picture taken by Pleiades satellite and released on September 27, 2013 shows a small island of mud and rock created by the huge earthquake that hit southwest Pakistan has fascinated locals but experts – who found methane gas rising from it – say it is unlikely to last long. The 7.7-magnitude quake struck on September 25 in Baluchistan's remote Awaran district, killing at least 271 people and affecting hundreds of thousands. The island is about 60 to 70 feet (18 to 21 metres) high, up to 300 feet wide and up to 120 feet long and sits about 650 feet from the coast. (Photo by AFP Photo/CNES/Distribution Astrium Services)

A woman shouts asking for help during an eviction in Rio de Janeiro, Brazil, Friday, April 11, 2014. Squatters in Rio de Janeiro are clashing with police after a Brazilian court ordered that 5,000 people be evicted from abandoned buildings of a telecommunications company. Officers have used tear gas and stun grenades to try to disperse the families. (Photo by Silvia Izquierdo/AP Photo)

The competition, which is run by the Royal Observatory Greenwich in association with BBC Sky at Night Magazine, is now in its sixth year and has received over 2,500 entries. Photo: Centre of the Heart Nebula by Ivan Eder (Hungary). Situated 7500 light years away in the “W”-shaped constellation of Cassiopeia, the Heart Nebula is a vast region of glowing gas, energized by a cluster of young stars at its centre. The image depicts the central region, where dust clouds are being eroded and moulded into rugged shapes by the searing cosmic radiation. (Photo by Ivan Eder)

An injured protestor grieves in pain as police fire tear gas to disperse protesting members of the Inter University Students Federation during an anti government protest in Colombo, Sri Lanka, Thursday, May 19, 2022. Sri Lankans have been protesting for more than a month demanding the resignation of President Gotabaya Rajapaksa, holding him responsible for the country's worst economic crisis in recent memory. (Photo by Eranga Jayawardena/AP Photo)

A woman who was injured after being trampled is helped away, after residents desperate for a planned distribution of food for those suffering under Kenya's coronavirus-related movement restrictions pushed through a gate and created a stampede, causing police to fire tear gas and leaving several injured, at a district office in the Kibera slum, or informal settlement, of Nairobi, Friday, April 10, 2020. (Photo by Brian Inganga/AP Photo)