An Israeli jail authority officer escorts a prison van containing Palestinian prisoners as it enters Hasharon jail on October 16, 2011 in Tel Mond, Israel. IDF soldier Gilad Shalit is to be freed from 5 years of captivity in Gaza in an exchange deal which will see the release of 477 Palestinian prisoners in an initial deal with another 550 to freed after the return of Shalit. (Photo by Uriel Sinai/Getty Images)

The under-construction Shard building on December 5, 2011 in London, England. The 80 storey skyscraper will be Europe's tallest mixed-use building when it is completed in May 2012; it will contain offices, restaurants, residential apartments as well as a five star hotel. (Photo by Dan Kitwood/Getty Images)

A hostage runs towards a police officer outside Lindt cafe, where other hostages are being held, in Martin Place in central Sydney December 15, 2014. Two more hostages have run out of the cafe at the center of a siege in Sydney, Australia's largest city, according to a Reuters witness at the site. The two women were both wearing aprons indicating they were staff at the Lindt cafe where a gunman has been holding an unknown number of hostages for several hours. Three men had earlier run out of the cafe. (Photo by Jason Reed/Reuters)

In this Sunday, March 29, 2015 photo, a young performer from the Parinacochas district of Ayacuhco dances in the Vencedores de Ayacucho dance festival, in the Acho bullring in Lima, Peru. The performers sang in the Quechua language, portraying the planting of corn and potatoes. From very young children to elderly people dressed as farmers, tigers, and foxes, as well as members of auto-defense groups, soldiers and police officers, to portray the violence that tore apart their families and communities. (Photo by Rodrigo Abd/AP Photo)

A military police officer patrols in the Roquette Pinto shantytown, part of the Mare slum complex in Rio de Janeiro, Brazil, Wednesday, April 1, 2015. The Brazilian army has begun to pull out of one of Rio de Janeiro's most violent slums, with police assuming responsibility for security in the area. (Photo by Felipe Dana/AP Photo)

A policer officer hits a man with a baton as he tries to maintain order while migrants wait for trains at a temporary camp near Gevgelija, Macedonia, September 7, 2015. Several thousand migrants in Macedonia boarded trains on Sunday to travel north after spending a night in a provisional camp. Macedonia has organised trains twice a day to the north border where migrants cross into Serbia to make their way to Hungary. Since June, Macedonian authorities have said that more than 60,000 migrants have entered the country, and around 1,500 entered just in one day, mainly refugees from Syria. (Photo by Stoyan Nenov/Reuters)

A woman shouts asking for help during an eviction in Rio de Janeiro, Brazil, Friday, April 11, 2014. Squatters in Rio de Janeiro are clashing with police after a Brazilian court ordered that 5,000 people be evicted from abandoned buildings of a telecommunications company. Officers have used tear gas and stun grenades to try to disperse the families. (Photo by Silvia Izquierdo/AP Photo)

Ranger trainees and trainee dogs simulate an ambush against rhino poachers at the Paramount Group Anti-Poaching training and K9 (canine) academy on November 26, 2014 in Magaliesberg, South Africa. One of the largest of its kind in Africa, the Academy will address the ever increasing need for training of Conservation Officers in anti poaching activities, wildlife contraband detection, specialist K9 solutions and Ranger K9 handler training – all of which have proven success rates in combatting and apprehending poachers and their activities. (Photo by Gianluigi Guercia/AFP Photo)