School teachers and staff members take part during an active shooter training at James I. O'Neill High School in Highland Falls, New York, U.S., December 12, 2017. (Photo by Eduardo Munoz/Reuters)

A man rides a horse through flames during the annual “Luminarias” celebration on the eve of Saint Anthony's day, Spain's patron saint of animals, in the village of San Bartolome de Pinares, northwest of Madrid, Spain, January 16, 2017. (Photo by Paul Hanna/Reuters)

A Hindu sadhu (holy man) smears coloured paste onto his face ahead of the forthcoming Hindu festival of “Maha Shivaratri” at the Pashupatinath temple in Kathmandu on February 11, 2018. Hindus mark the “Maha Shivratri” festival by offering special prayers and fasting, with sadhus arriving at Pashupatinath to take part in the event, which takes place on February 13. (Photo by Prakash Mathema/AFP Photo)

North Korea's Samjiyon Orchestra performs at Pyongyang Grand Theatre in Pyongyang, North Korea, September 18, 2018. (Photo by Pyeongyang Press Corps/Pool via Reuters)

This aerial picture taken on the night of November 12, 2018 shows traffic on an elevated intersection in downtown Shanghai, China. (Photo by Johannes Eisele/AFP Photo)

Dozens of people participate in the religious pilgrimage to the National Shrine of El Rincon, in the municipality of Boyeros, in Havana, Cuba, 17 December 2018. As is customary every year, thousands of people in mass attend the shrine to pay tribute to Saint Lazarus, to whom the faithful come for personal requests and miracles. (Photo by Ernesto Mastrascusa/EPA/EFE)

Police detain an alleged thief in Lagos' Tafawa Balewa Square where the official People's Democratic Party (PDP) opposition party is holding a rally on February 12, 2019. Nigerians will cast their ballots on February 16 in presidential and legislative elections. The presidential contest will see incumbent Muhammadu Buhari seek to win a second four-year term against former vice president Atiku Abubakar in what is expected to be a close race. (Photo by Luis Tato/AFP Photo)

A woman reacts to the sun coming out of the clouds during the annual Easter Parade and Bonnet Festival on Fifth Avenue in New York City, New York, U.S. April 21, 2019. (Photo by Stephanie Keith/Reuters)