A woman surveys the damage after the earthquake on March 17, 2011 in Kensennuma, Japan. Residents were allowed back to their homes today and began the massive cleanup operation caused by a 9.0 magnitude strong earthquake that struck on March 11 off the coast of north-eastern Japan. The quake triggered a tsunami wave of up to 10 metres which engulfed large parts of north-eastern Japan. The death toll has risen past 5000 with at least 8600 people still missing. (Photo by Chris McGrath/Getty Images)

Freshmen in Zhengzhou Institute of Aeronautical Industry Management head bottles of mineral water for upright stand during military training on September 17, 2015 in Zhengzhou, Henan Province of China. More than 6,800 freshmen in the school are required to take part in the military training. (Photo by ChinaFotoPress/ChinaFotoPress via Getty Images)

Indian artist, Ravi Kali (32), dressed as Hindu goddess Kali, participates in a religious procession for the Hindu festival, Ganesh Chaturthi in New Delhi on September 24, 2015. (Photo by Chandan Khanna/AFP Photo)

Children attend a war safety awareness class conducted by civil defence members, in the rebel-controlled area of Maaret al-Numan town in Idlib province, Syria May 14, 2016. (Photo by Khalil Ashawi/Reuters)

South Korean college students wearing masks hold up candles as they march after a rally calling for South Korean President Park Geun-hye to step down in Seoul, South Korea, Saturday, November 12, 2016. Hundreds of thousands of people flooded Seoul's streets on Saturday demanding the resignation of Park amid an explosive political scandal, in what may be South Korea's largest protest since it shook off dictatorship three decades ago. (Photo by Lee Jin-man/AP Photo)

An Iraqi girl, who fled from Falluja because of Islamic State violence, poses for a photographer at a refugee camp in Ameriyat Falluja, south of Falluja, Iraq, June 16, 2016. (Photo by Ahmed Saad/Reuters)

A migrant prays on his knees after boarding the Migrant Offshore Aid Station (MOAS) rescue ship Topaz Responder around 20 nautical miles off the coast of Libya, June 23, 2016. (Photo by Darrin Zammit Lupi/Reuters)

A containment shelter for the damaged fourth reactor (L) and the New Safe Confinement (NSC) structure (R) at the Chernobyl Nuclear Power Plant are seen from Ukraine's abandoned town of Pripyat, Ukraine, April 22, 2016. (Photo by Gleb Garanich/Reuters)