A riot policeman watches as a police vehicle burns in Braamfontein, Johannesburg, South Africa, Tuesday, October 25, 2016. Rioters in South Africa set a police vehicle on fire Tuesday and stoned vehicles near a Johannesburg university that has been the scene of sometimes violent protests by students demanding free education. The violence broke out in streets near the University of the Witwatersrand at around the same time that student protesters met and marched off the campus, South African media reported. (Photo by Yeshiel Panchia/AP Photo)

In this Wednesday, March 18, 2015 photo, limestone quarry workers walk through a cloud of dust spewed into the air by rotor blades of the stone-cutting machinery in the desert of Minya, southern Egypt. Around 45,000 people, including children, work in an estimated 1,500 quarries, digging out stones that later will be used in construction or powdered to be used by pharmaceutical and ceramic companies. (Photo by Mosa'ab Elshamy/AP Photo)

Mohamed Mostafa, 35, carries dyed yarns at a dye workshop in old Cairo, Egypt, March 17, 2016. Egypt's hard currency crisis and competition from modern factories in Asia and at home threaten one of the last dye workshops in Egypt. But one of its owners takes comfort in the trade's ancient resilience. Mohamed Mostafa boasts that the profession dates back 3,000 years, so it can survive anything. (Photo by Amr Abdallah Dalsh/Reuters)

A firefighter uses a saw to open a metal gate while fighting a fire in a convenience store and residence during clashes after the funeral of Freddie Gray in Baltimore, Maryland in the early morning hours of April 28, 2015. (Photo by Eric Thayer/Reuters)

A protester performs the symbolic death of a student demonstrator during a march near Congress where Chile's President Michelle Bachelet gives her annual address in Valparaiso, Chile, Thursday, May 21, 2015. Demonstrators are protesting the death of two students killed during an education reform march last week in Valparaiso and demanding more involvement in education reform. (Photo by Luis Hidalgo/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)

Dinosaur costumed actors representing Thailand's establishment at a high school student led protest in Bangkok, Thailand on November 21, 2020. (Photo by Matthew Tostevin/Reuters)

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)