Trainers from Tianjiao Special Guard/Security Consultant Ltd. Co. engage trainees dressed in swimming suits as they crawl on the beach during a training session in Sanya, Hainan province January 8, 2012. (Photo by CHINA DAILY/Reuters)

This undated handout picture taken by Tim Samuel and provided through his Instagram account shows a small fish swimming inside the belly of a jellyfish off the coast of Byron Bay in New South Wales, eastern Australia. A fish has been pictured swimming inside a jellyfish off Australia's east coast in a remarkable and rare image that has gone viral, with more than two million online views. Underwater photographer Tim Samuel was in the water with a friend near popular tourist resort Byron Bay in December when they came across the little creature trapped inside the only slightly larger jellyfish. (Photo by Tim Samuel Photography/AFP Photo/Instagram)

Syrian civil defence volunteers, known as the White Helmets, rescue a boy from the rubble following a reported barrel bomb attack on the Bab al- Nairab neighbourhood of the northern Syrian city of Aleppo on November 24, 2016. (Photo by Ameer Alhalbi/AFP Photo)

A boy moves away as a United Nations World Food Programme (WFP) helicopter lands in Rubkuai village, Unity State, northern South Sudan, February 18, 2017. South Sudan on Monday declared famine in some parts of the country, with more than three years of war leaving nearly five million hungry in what aid groups called a “man-made” tragedy. (Photo by Siegfried Modola/Reuters)

A picture taken on March 9, 2017, shows a boy playing with a cat next to a 1948 Buick parked outside the home of Mohammad Mohiedine Anis in the formerly rebel-held al-Shaar neighbourhood. (Photo by Joseph Eid/AFP Photo)

A baboon clings to the leg of an internally displaced boy at a camp on the outskirts of the town of Qol Ujeed, on the border with Ethiopia, Somaliland April 17, 2016. Across the Horn of Africa, millions have been hit by the severe El Nino-related drought. In Somaliland and its neighbouring, also semi-autonomous, Puntland region, 1.7 million people are in need of aid, according to the United Nations. In Somaliland itself, the most affected areas include the northwest Awdal region bordering Ethiopia. (Photo by Siegfried Modola/Reuters)

Boys pose with their toy guns as others play on swings, on the first day of the Muslim holiday of Eid al-Fitr, which marks the end of the holy month of Ramadan, in the government-controlled district of Dwelaa in Damascus, Syria July 6, 2016. (Photo by Omar Sanadiki/Reuters)

An Afghan policeman stands guard in front of a French restaurant “Le Jardin” after a suicide attack in Kabul, Afghanistan January 2, 2016. A suicide attack on a French restaurant in the Afghan capital Kabul on Friday killed a 12-year-old boy and wounded more than a dozen other people, officials said. (Photo by Mohammad Ismail/Reuters)