A Saudi soldier fires a mortar towards Houthi movement position, at the Saudi border with Yemen April 21, 2015. (Photo by Reuters/Stringer)

An injured girl reacts at a site hit by an airstrike in the rebel-held Douma neighbourhood of Damascus, Syria November 7, 2016. (Photo by Bassam Khabieh/Reuters)

A picture made available on 08 July 2015 showsa lightning strikes during a heavy storm over Poznan in the night of 07 July 2015. Severe storms passed last night over Poland causing lots of damages to buildings, trees, electricity and railway tractions. (Photo by Lukasz Ogrodowczyk/EPA)

Lightning strikes during a storm over the Ionian Sea in Calabria, Italy on June 27, 2016. (Photo by Alfonso Di Vincenzo/Pacific Press/Rex Features)

Tamberly Conway, bottom left, takes part in a large snowball fight in Dupont Circle on Sunday January 24, 2016 in Washington, DC. The Washington, DC area was blanketed by a large snow event. (Photo by Matt McClain/The Washington Post)

A resident jumps as he watches strong waves crash into shore as an effect of Typhoon Hagupit in Legazpi, Albay province, eastern Philippines on Sunday, December 7, 2014. Typhoon Hagupit knocked out power in entire coastal provinces, mowed down trees and sent more than 650,000 people into shelters before it weakened Sunday, sparing the central Philippines a repetition of unprecedented devastation by last year's storm. (Photo by Aaron Favila/AP Photo)

Laura Halford of Wales jumps during her hoop routine as she competes in the rhythmic gymnastics individual all-around final event at the 2014 Commonwealth Games in Glasgow, Scotland, July 25, 2014. (Photo by Phil Noble/Reuters)

A car stands in water on Ferry Road after two magnitude 6.0 and 5.5 earthquakes struck on June 13, 2011 in Christchurch, New Zealand. The aftershocks have followed four months after the major eathquake which hit the city on February 22, 2011 resulting in the deaths of 181 people. (Photo by Martin Hunter/Getty Images)