A prisoner from the Pedrinhas prison is carried to receive medical help after he was injured during a fight between rival gangs inside the jail, in Sao Luiz, capital of Maranhao state, January 8, 2014. The recent posting on a major Brazilian news website of a video filmed last December 17 by Pedrinhas prisoners of the decapitated and tortured bodies of rival inmates inside the jail has highlighted some of the problems present in the country's prison system which houses nearly twice as many prisoners as its capacity, according to official statistics. (Photo by Douglas Cunha/Reuters/O Estado do Maranhão)

Smoke rises from a house days after part of the ground it was resting on collapsed into Lake Whitney, Texas in this June 13, 2014 file photo. I was covering the controlled burn of a house slowly falling into Lake Whitney due to the decaying cliff underneath. Asked to take photos from an aerial perspective, an instructor and I took off from Grand Prairie Municipal Airport around 9am. The burn, scheduled to start an hour later, was delayed. I love flying, but patience proved challenging as circling for nearly three hours gets boring fast. Once the fire started we only had 15 minutes to take photos because the plane was booked at 1pm. The owners invested their retirement savings in the house and were even advised by geologists that the ground was stable. To watch your investment literally go up in flames must take its toll emotionally. The owners said they don't expect their insurance to cover the loss. (Photo and caption by Brandon Wade/Reuters)

Buddhist novice poses for a picture while monks gather to receive alms at Wat Phra Dhammakaya temple, in what organizers said was a meeting of over 100,000 monks, in Pathum Thani, outside Bangkok April 22, 2016. (Photo by Jorge Silva/Reuters)

Personal possessions of 2004 tsunami victims are arranged to be photographed outside a police station in Takua Pa, in Phang Nga province December 19, 2014. Thai police opened a shipping container filled with documents and possessions of victims of the 2004 Indian Ocean Tsunami after being asked by Reuters for permission to film its contents. The three metre by 12 metre container was handed over to Thai police in 2011 and contains hundreds of plastic police evidence bags – each one holding the precious items found on the body of a victim. (Photo by Damir Sagolj/Reuters)

A mahout rides an elephant at Tad Sae Waterfall outside Luang Prabang, Laos July 31, 2016. Protected by the United Nations cultural heritage agency UNESCO, Luang Prabang is one of the most alluring places in the region – a city that evokes old-world romance that has gained a reputation as a travellers' Shangri La. (Photo by Jorge Silva/Reuters)

Models promote a condom brand at the first Shenzhen s*x Culture Festival on September 21, 2007 in Shenzhen of Guangdong Province, China. The festival aims to increase awareness about reproductive health and popularise s*x education. (Photo by China Photos/Getty Images)

A devotee holds incense sticks while celebrating the Sindoor Jatra Festival on April 15, 2015 in Thimi, Nepal. Sindoor Jatra Festival is celebrated each year in Thimi, on the outskirts of Kathmandu, to welcome the Nepali New Year and celebrate the coming of spring. During the Festival, devotees are smeared with vermillion powder and 30 chariots containing the images of several gods and goddesses are carrying by the devotees around the town, while others sing, dance and play musical instruments. (Photo by Omar Havana/Getty Images)

Students pose for a picture with a 3- D optical illusion artwork of a devastated cityscape in Aleppo, Syria at the campus of the Meiji University in Tokyo on November 18, 2016. The Japanese branch of the human rights organisation Amnesty International displayed the artwork to encourage people to think about the Syrian civil war. (Photo by Toshifumi Kitamura/AFP Photo)