A doctor performs surgery on an injured man with a part of an aluminium alloy fence through his chest after a car accident in Zhumadian, Henan province, China, September 15, 2014. The doctor managed to surgically remove the piece. (Photo by Reuters/Stringer)

Yaks head towards the Everest base camp in Solukhumbu District April 28, 2014. (Photo by Navesh Chitrakar/Reuters)

Italian disabled dancer Simona Atzori (top) performs, before a special audience with disabled athletes led by Pope Francis, in Paul VI hall at the Vatican October 4, 2014. (Photo by Tony Gentile/Reuters)

World War II veterans danced during Victory Day celebrations in Minsk, Belarus, Thursday, May 9, 2013. Belarus and other former Soviet countries celebrated the 1945 victory over Nazi Germany on Thursday. (Photo by Viktor Drachev/AFP Photo)

A woman walks against blowing snow in Evanston, Illinois, on February 8, 2014. (Photo by Nam Y. Huh/Associated Press)

A masked Burundian protester faces soldiers in front of a burning barricade during an anti-government demonstration against President Pierre Nkurunziza's bid for a third term in the capital Bujumbura, Burundi, 25 May 2015. Street protests continued on 25 May as the United Nations Secretary-General Ban Ki-moon condemned the killing of the leader of the oppsition party Union for Peace and Development (UPD) Zedi Feruzi who opposed Nkurunziza's bid. (Photo by Dai Kurokawa/EPA)

An undercover police officer, who had been marching with anti-police demonstrators, aims his gun at protesters after some in the crowd attacked him and his partner in Oakland, California December 10, 2014. Police said more than 100 demonstrators marched in Berkeley, California, which has a history of social activism. Under cloudy skies, turnout was smaller than earlier in the week, when demonstrators in the area threw rocks at police and shut down a major freeway. (Photo by Noah Berger/Reuters)

Family of passengers onboard AirAsia flight QZ8501 react at a waiting area in Juanda International Airport, Surabaya December 28, 2014. Indonesia's air force was searching for the AirAsia plane carrying 162 people that went missing on Sunday after the pilots asked to change course to avoid bad weather during a flight from the Indonesian city of Surabaya to Singapore. The Airbus 320-200 lost contact with Jakarta air traffic control at 6:17 a.m. (23:17 GMT), officials said. (Photo by Reuters/Beawiharta)