Fire fighters, emergency service vehicles and a helicopter in Moskovsky Prospekt at the entrance to Tekhnologichesky Institut station of the St Petersburg metro in the aftermath of an explosion which occurred in a train at 14:40 Moscow timeon April 3, 2017. (Photo by Peter Kovalev/TASS)

People spray water in the street ahead of “Songkran”, the annual Thai New Year water-throwing festival, in Kowloon City, Hong Kong, China, 09 April 2017. The pouring of water is a key element in the festival as it represents purification and the washing away of one's sins and bad luck for the year. The event also includes a “Miss Songkran” pageant where contestants are clothed in traditional Thai dress, and a winner is crowned. This year's “Songkran” will begin in Thailand on 13 April 2017. (Photo by Alex Hofford/EPA)

A skier in a costume attempts to cross a pool of water at the foot of a ski slope while competing in the annual “Gornoluzhnik” amateur event marking the end of the ski season, at the Bobrovy Log ski resort in the suburbs of the Siberian city of Krasnoyarsk, Russia, April 16, 2017. (Photo by Ilya Naymushin/Reuters)

Iraqi paramilitary troops fire towards Islamic State militants during a battle with Islamic State militants on the outskirts of the ancient city of Hatra near Mosul,Iraq April 26, 2017. (Photo by Reuters/Stringer)

Lali carries balloons to sell on a beach in Mumbai, India, Sunday, October 11, 2015. The United Nations General Assembly marks October 11 as the International Day of the Girl Child, to recognize girls’ rights and the unique challenges girls face around the world. (Photo by Rafiq Maqbool/AP Photo)

People watch police destroy confiscated illegal firecrackers in Shenyang, Liaoning province, China, January 29, 2016. (Photo by Reuters/Stringer)

A journalist sits next to a dummy during a virtual Toyota test drive, during the press day at the 86th Geneva International Motor Show in Geneva, Switzerland, 01 March 2016. The Motor Show will open its gates to the public from 3th to 13th March presenting more than 200 exhibitors and more than 120 world and European premieres. (Photo by Martial Trezzini/EPA)

An Indian underprivileged bride gets her jewellery adjusted by a relative during a mass marriage ceremony in New Delhi, India, March 10, 2016. Fourteen underprivileged couples tied up the nuptial knot in the mass marriage ceremony organised by various social organisations. (Photo by Rajat Gupta/EPA)