A young vendor hawks food on a market in Kara in the state of Ogun, on September 23, 2015. Nigeria imposed tight movement restrictions in the restive northeast after Boko Haram bombings that killed more than 100 raised fears of fresh attacks over the Eid al-Adha festival. The military said the use of all vehicles would be banned throughout Borno state during the Muslim festival, which is known as Sallah in Nigeria and marked with two days' public holiday from Thursday. (Photo by Pius Utomi Ekpei/AFP Photo)

A Lebanese man carries an injured woman away from the site of a car bomb explosion in a Shiite area and stronghold of the Lebanese militant group Hezbollah at the southern suburb of Beirut, Thursday January 2, 2014. A large explosion has rocked a stronghold of the Shiite Hezbollah group in the southern suburbs of the Lebanese capital. (Photo by Hussein Malla/AP Photo)

Dhruva Aliman does a back somersault as he dismounts from a slackline on the beach at Santa Monica, California on October 19, 2014. Slackline is a balance sport where a line of webbing is adjusted at different levels of tension between two anchor points and participants (called slackers) perform tricks and stunts including somersaults. (Photo by Mark Ralston/AFP Photo)

Among the fish populations that could be harmed by the Xayaburi dam in Laos is the critically endangered Mekong giant catfish, considered by the Guinness Book of World Records to be the world’s largest freshwater fish. The fish, which grows to 650 pounds and about 10 feet long, is only found in the Mekong River. It is migratory, moving between downstream habitats in Cambodia upstream to northern Thailand and Laos each year to spawn. Some experts fear the Xayaburi dam could block the migration and drive the giant catfish to extinction. (Photo by Courtesy of Zeb Hogan/University of Nevada, Reno)

A Saudi police officer receives emergency calls at a call center, ahead of the Hajj pilgrimage in the Muslim holy city of Mecca, Saudi Arabia, Tuesday, August 6, 2019. The hajj occurs once a year during the Islamic lunar month of Dhul-Hijja, the 12th and final month of the Islamic calendar year. (Photo by Amr Nabil/AP Photo)

A young female demonstrator is arrested by police during clashes in the Causeway Bay area of Hong Kong, China on October 6, 2019. Hundreds of thousands of protesters marched through the city's streets in defiance of the new “no-mask” law, which was introduced two days ago as demonstrations roll into a 14th week. (Photo by Rick Findler/EPA/EFE/Rex Features/Shutterstock)

A woman cries after her husband was shot dead by unidentified gunmen riding motorcycles in Manila, Philippines late October 10, 2016. According to police reports, around 2,300 people have been killed in Philippine President Rodrigo Duterte's war against illegal drugs. The figure was revised by the police from an original tally of around 3,600 deaths. (Photo by Damir Sagolj/Reuters)

A person viewing the Northern lights over the lava landscape, Reykjanes Peninsula, Iceland. (Photo by Arctic-Images/Getty Images)