A woman loyal to the Houthi movement holds a rifle as she takes part in a parade to show support to the movement in Sanaa, Yemen September 6, 2016. The Saudi-led Arab coalition launched a military campaign against the Huthis and their allies in March 2015, after the rebels closed in on Gulf-backed President Abedrabbo Mansour Hadi in his southern refuge of Aden, forcing him into exile. (Photo by Khaled Abdullah/Reuters)

In this July 30, 2014 photo, neighbors help gravely injured Mohammed al-Selek, 39, wounded by an Israeli mortar strike as he lays next to the body of Palestinian journalist Rami Reyan who was killed, in the Shijaiyah neighborhood of the northern Gaza Strip. Al-Selek's life changed forever last July 30, when the shells slammed into his home killing all his three children, his father and six other relatives. A year later, al-Selek, who lost his leg during the airstrike, still struggles to recover and come to terms with his family's loss in the 50-day Israel-Hamas war. (Photo by Adel Hana/AP Photo)

A pigeon, known as Siyah Kinifirli, with an approximate market value of 1000 Turkish Lira ($263), bred by 23-year-old Ismail Ozbek, is pictured in Sanliurfa, Turkey, December 23, 2016. As night-time approaches in Sanliurfa, southeastern Turkey, most of the alleyways of the city's old bazaar are emptying out of buyers and vendors, except for one. (Photo by Umit Bektas/Reuters)

An animal rights activist washes herself with red dye to mimic blood during a protest against the testing of shampoo on animals in Barcelona. April 24, 2012. (Photo by Raul Albaledo/AFP Photo)

Mazouza Bouglada, 86, a berber woman from the Chaouia region, who has facial tattoos, poses for a photograph in Taghit in the Aures Mountain, Algeria October 8, 2015. Bouglada was tattooed aged 7 by a nomadic man from the Sahara region. She was advised by her mother to get tattooed. The more she got tattooed the more she showed off. Even if she still remembers the pain, she felt beautiful once it was done, Bouglada said. She was very proud of her stars on her cheeks. Her eldest sister had been tattooed before her and she wanted to imitate her. Bouglada said she has now given away all her silver jewellery to atone for the sin that believers told her she had committed by being tattooed. (Photo by Zohra Bensemra/Reuters)

Staff of a boat restaurant on the Taedong River line up at the entrance as they wait to greet customers Sunday, June 18, 2017, in Pyongyang, North Korea. The boat is berthed along the river, which is the fifth longest river on the Korean Peninsula and runs through the country's capital, Pyongyang. (Photo by Wong Maye-E/AP Photo)

The possible surface of TRAPPIST-1f, one of seven newly discovered planets in the TRAPPIST-1 system that scientists using the Spitzer Space Telescope and ground based telescopes have discovered. (Photo by Reuters/NASA/JPL-Caltech)

Serbian police officers of the Special Anti-Terrorist Unit pose for a picture in their base outside Belgrade October 8, 2014. When the killing of an unarmed black teenager by a white policeman in Ferguson, Missouri, in August sparked sometimes violent protests, the response of police in camouflage gear and armoured vehicles wielding stun grenades and assault rifles seemed more like a combat operation than a public order measure. Some U.S. police departments have recently acquired U.S. military-surplus hardware from wars abroad, but there are many law enforcers around the world whose rules of engagement also allow the use of lethal force with relatively few restrictions. But for every regulation that gives police wide scope to use firearms, there is another code that sharply limits their use. In Serbia, police may use measures ranging from batons to special vehicles, water cannon and tear gas on groups of people who have gathered illegally and are behaving in a way that is violent or could cause violence, but they may use firearms only when life is endangered. (Photo by Marko Djurica/Reuters)