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)

A schoolgirl collects rubbish from Karachi's Clifton beach early morning April 22, 2013, during a cleaning campaign as part of the commemoration of Earth Day. (Photo by Akhtar Soomro/Reuters)

A student is assisted by teachers after she fell ill while marching in a parade celebrating Saint Peter's day in Lima, Peru, Monday, June 29, 2015. During the feast day of the Catholic saint, who is the patron saint of fishermen, coastal communities pay homage to St. Peter, whose statue is paraded to the sea and petitions are made to keep their vessels and all who work on them safe. (Photo by Rodrigo Abd/AP Photo)

Believers burn dried oak branches, which symbolizes the Yule log, on Orthodox Christmas Eve in front of the St. Sava temple in Belgrade, Serbia, January 6, 2016. Serbian Orthodox believers celebrate Christmas on January 7, according to the Julian calendar. (Photo by Marko Djurica/Reuters)

A girl collects drinking water at Dala river outside Yangon, Myanmar March 3, 2016. Some 650 million people, or one in 10 of the world's population, have no access to safe water, putting them at risk of infectious diseases and premature death. Dirty water and poor sanitation can cause severe diarrhoeal diseases in children, killing 900 under-five a day across the world, according to United Nations estimates. (Photo by Soe Zeya Tun/Reuters)

On September 1, 2004, Chechen militants stormed an elementary school in the town of Beslan in the Russian republic of North Ossetia. They took 1,100 teachers, children, and their relatives hostage, demanding the withdrawal of federal forces from Chechnya as a condition for their release. On September 3, 2004, Russian security forces stormed the building, resulting in a battle in which more than 330 hostages died, including 186 children. Here: A man assists two young hostages who managed to escape from the school building after special forces entered the school in Beslan, North Ossetia, Friday 03 September 2004. (Photo by Yuri Kochetkov/EPA)

Fr. Denis Crosby blesses a live lamb during a Pattern Day mass to St. Brigid at the holy well of St. Brigid in Liscannor, Ireland February 1, 2017. (Photo by Clodagh Kilcoyne/Reuters)

A dancer prays before she performs as land activists gather to commemorate the upcoming Women's Day in Phnom Penh, Cambodia, March 7, 2017. (Photo by Samrang Pring/Reuters)