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)

Mount Sinabung is seen during an eruption from Surbakti village in Karo, North Sumatra, Indonesia, April 20, 2015. The local government is preparing the relocation of residents from three of the villages that were destroyed. (Photo by Tibta Pangin/Getty Images/Anadolu Agency)

A participant of the “Mrs Universe 2015” contest from Caribbean Coast, Mayra Joli poses for a photo with a woman during their visit in central botanical garden in Minsk, Belarus, August 25, 2015. (Photo by Vasily Fedosenko/Reuters)

A visitor holds up her toy bunny to the aquarium glass in front of Aurora the Russian polar bear at the Sao Paulo Aquarium in Sao Paulo, Brazil, Thursday, April 16, 2015. (Photo by Andre Penner/AP Photo)

A spotted owlet appears to be playing peek-a-boo near Rancharda Lake in Ahmedabad, India on February 9, 2016. The species is common across the Indian subcontinent. (Photo by Caters News Agency)

A six-year-old acrobat performs on the opening of a tourist festival in Bozhou, Anhui province, China May 3, 2015. (Photo by Reuters/China Daily)

Devotees ride on the roof of a train as they return to the city after attending the final prayers on the first phase of Bishwa Ijtema in Dhaka January 11, 2015. Hundreds of thousands of pilgrims congregated in the Bangladeshi capital Dhaka as the first phase of this year's Bishwa Ijtema, one of the biggest Islamic gatherings in the world after the Haj in Saudi Arabia, came to an end. (Photo by Reuters/Stringer)

Polar bear twins make their first public appearance with their mother “Freedom” at Ouwehands Zoo Rhenen, in Rhenen, The Netherlands, 19 February 2015. The twins, who were born in November 2014, have not been named because their gender has not yet been determined. (Photo by Bart Maat/EPA)