Paramilitary policemen carry tyres as they take part in a training session in Zhangye, Gansu Province, China, March 1, 2016. (Photo by Reuters/Stringer)

An anti-Gaddafi fighter tests an anti-aircraft gun southwest of Sirte, Libya one of Muammar Gaddafi's last remaining strongholds, September 16, 2011. A timeline of images dating from 2010 from Sirte, Libya, the home town of deposed Libyan leader Muammar Gaddafi. Libyan forces battling Islamic State in the city of Sirte say they have defeated the militant group after months of street to street fighting backed by U.S. air strikes. Islamic State took control of the city more than a year ago and set up its main base outside Syria and Iraq. (Photo by Goran Tomasevic/Reuters)

The Sugar Plum Fairy, Katherine Free, left, dances with the dog, Pig, during the Birmingham's Ballet “Mutt-cracker”, a rendition of the famous ballet “The Nutcracker”, in Birmingham, Alabama, December 8, 2016. (Photo by Brynn Anderson/AP Photo)

Pakistani civil society activists release lanterns into the sky in Lahore on December 15, 2016, as they pay tribute to victims on the second anniversary of an attack on The Army Public School in the city of Peshawar. Taliban militants attacked on Pakistani Army Public School in Peshawar, killing 151 people mostly children on December 16, 2014. (Photo by Arif Ali/AFP Photo)

Visitors run away as waves caused by a tidal bore surge past a barrier on the banks of Qiantang River, in Hangzhou, Zhejiang province August 13, 2014. (Photo by Reuters/Stringer)

A group of youngsters dressed as ghouls and zombies for Halloween parade in downtown Lisbon, Portugal, Friday, October 31, 2014. (Photo by Francisco Seco/AP Photo)

Women sunbath as Ferrari's Brazilian driver Felipe Massa drives past during the third practice session at the Circuit de Monaco in Monte Carlo on May 25, 2013 ahead of the Monaco Formula One Grand Prix. (Photo by Alexander Klein/AFP Photo)

White smoke billowed from the chimney on the Sistine Chapel indicating that a new pope has been elected in St. Peter's Square at the Vatican, Wednesday, March 13, 2013. (Photo by Dmitry Lovetsky/AP Photo)