A woman carries her child as she walks alongside a line of shacks in the impoverished township of Diepsloot on the outskirts of Centurion on April 24, 2014. South Africans will mark 20 years of democracy since the first post-Apartheid election on April 27, 1994. (Photo by Mujahid Safodien/AFP Photo)

Police officers control a crowd near the scene of the inspection of a vehicle suspected to be packed with explosives on April 24, 2014 in Nairobi's Somali district of Eastleigh a day after another car bomb was detonated killing two police officers at a nearby police station. Following a tip-off from the public, bomb experts set about inspecting the vehicle which they said bore signs of having been used to transport a large load, possibly an explosive device, before towing it away for further forensic inspection. At least four people, including two policemen, were killed on Wednesday when a car bomb exploded outside a police station in Nairobi near a major Somali neighbourhood. (Photo by Tony Karumba/AFP Photo)

Local workers lift a damaged US-made AH-64E Apache attack helicopter from a roof in Taoyuan, northern Taiwan, on April 25, 2014. Two Taiwanese pilots were injured when their Apache attack helicopter crash landed on a building in northern Taiwan during a routine training mission, the military said. (Photo by Sam Yeh/AFP Photo)

Emergency responders rescue a man buried under rubble after a building collapsed following a reported barrel-bomb attack on the northern Syrian city of Aleppo, on April 25, 2014. Syria's Aleppo has been hit by a power cut for seven consecutive days, the Syrian Observatory for Human Rights group said, the day after some 50 civilians were killed in air raids there. (Photo by Baraa Al-Halabi/AFP Photo)

Dancers prepare before a performance in the backstage area of the Buick exhibition during the “Auto China 2014” Beijing International Automotive Exhibition in Beijing on April 21, 2014. Leading automakers have gathered in Beijing for the kickoff of China's biggest car show, but lackluster growth and environmental restrictions in the world's largest car market have thrown uncertainty into the mix. (Photo by AFP Photo)

Topless activists of the Ukrainian women movement Femen take part in a “Fascist's epidemic” action, on April 22, 2014 in Paris, to disturb a press conference of French far-right National Front (FN) party, marking the start of the FN's electoral campaign for the European elections. The European Parliamentary elections will take place from May 22 to May 25, 2014. (Photo by Thomas Samson/AFP Photo)

People ride a motorbike as French soldiers part of the Sangaris operation stand guard in Bangui on April 21, 2014. The United Nations has evacuated almost 100 Muslims from the capital of the crisis-torn Central African Republic to “save their lives”, according to officials on April 22, 2014. The former French colony, one of the poorest countries in the world, plunged into a crisis after a coup by the mostly Muslim Seleka rebels in March last year. After seizing power, some of the rebels went rogue and embarked on a campaign of killing, raping and looting. (Photo by Miguel Medina/AFP Photo)

Fans take pictures of South Korean actor Kim Soo-hyun (not seen) during a fan meeting at a promotional event in Hong Kong April 23, 2014. (Photo by Tyrone Siu/Reuters)

A man pours water on a competitor during a road race as part of traditional festival games to celebrate the Sinhala, the Hindu and Tamil New Year, in Homagama April 20, 2014. Sri Lankans observed their New Year on April 14. (Photo by Dinuka Liyanawatte/Reuters)

Explosives are detonated to demolish part of the Perimetral overpass, as part of Rio's Porto Maravilha (Marvelous Port) urbanisation project, in Rio de Janeiro April 20, 2014. The project is for the city's redevelopment ahead of the 2016 Olympic Games. (Photo by Ricardo Moraes/Reuters)

People gather to observe the Perimetral overpass, after its partial demolition as part of Rio's Porto Maravilha (Marvelous Port) urbanisation project, in Rio de Janeiro April 20, 2014. (Photo by Ricardo Moraes/Reuters)

A family member of a missing passenger onboard the Sewol ferry which capsized on Wednesday, cries as she checks the newly announced list of the dead, at a gym in Jindo April 20, 2014. South Korean prosecutors investigating the ferry disaster said on Sunday they would seek to extend the detention of the ship's captain and two other crew by 10 days as they tried to determine the cause of the accident that may claim more than 300 lives. (Photo by Kim Kyung-Hoon/Reuters)

Cosplay enthusiasts practice for Hinode, a festival celebrating Japanese pop culture, in Moscow, April 20, 2014. (Photo by Artur Bainozarov/Reuters)

A Pro-Russian militant walks past burnt cars near a checkpoint that was the scene of a gunfight overnight near the city of Slaviansk, April 20, 2014. At least two people were killed in a gunfight early on Sunday near a Ukrainian city controlled by pro-Russian separatists, testing an already fragile international accord that is supposed to defuse Ukraine's armed stand-off. (Photo by Gleb Garanich/Reuters)

A Ukrainian Orthodox priest sprinkles holy water on believers during Easter in Donetsk, eastern Ukraine April 20, 2014. (Photo by Marko Djurica/Reuters)

A skier tries to cross a 26-metre long pool of water at the foot of a ski slope at the Bobrovy Log ski resort near Russia's Siberian city of Krasnoyarsk, April 20, 2014. 94 skiers and snowboarders took part in the annual “Gornoluzhnik” amateur event to mark the end of the ski season at the Siberian resort. (Photo by Ilya Naymushin/Reuters)

President Barack Obama and ASIMO, an acronym for Advanced Step in Innovative MObility, bow to each other during a youth science event at the National Museum of Emerging Science and Innovation, known as the Miraikan, in Tokyo, Thursday, April 24, 2014. Showing solidarity with Japan, Obama affirmed Thursday that the U.S. would be obligated to defend Tokyo in a confrontation with Beijing over a set of disputed islands, but urged all sides to resolve the long-running dispute peacefully. (Photo by Carolyn Kaster/AP Photo)

Ukrainian troops take position next to burning tires at a pro Russian checkpoint following an attack by Ukrainian troops outside in Slovyansk, Ukraine, Thursday, April 24, 2014. Ukrainian government troops moved against pro-Russia forces in the east of the country on Thursday and killed at least two of them in clashes at checkpoints manned by the insurgents, the government and insurgents said. Russian President Vladimir Putin decried what he described as a “punitive operation”. (Photo by Mika Velikovskiy/AP Photo)

Women read a leaflet distributed by pro-Russian activists behind barricades in front of a regional administration building that was seized by pro-Russian activists earlier in Donetsk, Ukraine, Wednesday, April 23, 2014. Russia's foreign minister on Wednesday promised a firm response if its citizens or interests come under attack in Ukraine – a vow that came after Ukraine announced a renewal of its “anti-terror” campaign against those occupying buildings in its troubled east. (Photo by Alexander Zemlianichenko/AP Photo)

A performer dressed in traditional ancient Roman costume prepares to parade along the ancient Roman ruins of the Colosseum, Circus Maximus and the Roman Forum to celebrate the festivities of the Christmas of Rome, at Circus Maximus, Monday, April 21, 2014. Legend says that Rome was founded by Romulus on April 21, 753 BC in an area surrounded by seven hills. Every year the city celebrates the Birth of Rome with parades and fighting in costume, re-enacting the deeds of the great ancient Roman Empire. (Photo by Andrew Medichini/AP Photo)

A sculpture decorated with newspaper clippings is on display near the site where anti-government student protesters are camping out in Bolivar square in the Chacao municipality of Caracas, Venezuela, Thursday, April 24, 2014. The opposition is resuming talks with President Nicolas Maduro's government on Thursday, aimed at defusing the nation's political crisis. It's the fourth face-to-face meeting this month and expected to focus on calls by the opposition for amnesty for jailed activists. (Photo by Fernando Llano/AP Photo)

Charlotte Wood from Leicester, models a fifty shades of green hat made from flowers and foliage, as the Harrogate Spring Flower show prepares for Britain's biggest display of floral art at Great Yorkshire Showground, Harrogate, on April 23, 2014. (Photo by Lynne Cameron/PA Wire)

A general view of the Forum of Augustus during the event “Forum of Augustus – 2,000 Years Later”, in Rome, Italy, 21 April 2014. The show with special light effects, music and reconstructions focuses on the figure of Augustus, the founder of the Roman Empire and its first Emperor, whose two thousandth death anniversary (19 August 14 AD) is marked this year. (Photo by Alessandro Di Meo/EPA)

Tourists stand at a lookout as steam rises from the Santiago Crater at Masaya Volcano National Park on Earth Day, near Managua April 22, 2014. (Photo by Oswaldo Rivas/Reuters)

A girl leaps over headstones at the Jakarta War Cemetery following the ANZAC Day dawn service in Jakarta, Indonesia, Friday, April 25, 2014. ANZAC Day honors the men of the Australia-New Zealand Army Corps who died in World War I at the 1915 battle for Gallipoli, Turkey. It has since come to honor the sacrifices made by all service members in the Australian and New Zealand Armed Forces. (Photo by Mark Baker/AP Photo)

Mohammad Malook 55, poses for a photograph as he works at a brick factory on the outskirts of Kabul, Afghanistan, Monday, April 21, 2014. Men generally work for 8 hours a day, six days a week, and make about 350 Afghani ($6) per day. (Photo by Rahmat Gul/AP Photo)

In this picture taken on April 20, 2014, Chinese Cantonese opera singers watch from the side of the stage before their performance during the Tin Hau festival on Lamma Island, an outlying island of Hong Kong. Tin Hau, whose birthday is celebrated this year on April 22, is known as the Goddess of the Sea and maintains high popularity ratings amongst Hong Kongers due to the close association between the territory and the sea – two other sea-faring places, Macau and Vietnam also hold Tin Hau in high-regard. (Photo by Anthony Wallace/AFP Photo)

Syrian refugees who fled from the Syrian town of Rankous, stand next to trucks which carry their belongings, in Tfail village, at the Lebanese-Syrian border, eastern Lebanon, Tuesday April 22, 2014. A Lebanese convoy of soldiers, clerics and Red Cross officials delivered aid Tuesday to a remote village near the Syrian border that was bombed by Syrian government aircraft and blocked by Lebanese militants fighting alongside President Bashar Assad’s forces in the civil war next door. Hezbollah fighters have been patrolling the area on the Lebanese side and fighting has flared up inside Syria, cutting Tfail’s residents off from all sides for months. (Photo by Hussein Malla/AP Photo)

Paramilitary policemen take off U.S. dollars strapped around a man's legs, at the border of Hong Kong and Shenzhen, Guangdong province, April 24, 2014. According to local media, the man was found trying to smuggle in total of US$580,000 from mainland to Hong Kong. (Photo by Reuters/China Daily)

A procession of motorcycle officers leads the hearse carry the coffin of Los Angeles Police Dept. motorcycle officer Chris Cortijo after a funeral service at the Cathedral of Our Lady of the Angels Tuesday morning, April 22, 2014, in Los Angeles. Hundreds of fellow law enforcement officers turned out to mourn 51-year-old officer, who who died after he struck by a motorist allegedly under the influence of cocaine on April 5. (Photo by Damian Dovarganes/AP Photo)

A man wounded after a car bomb attack during a Shi'ite political organisation's rally reacts at the site in Baghdad, April 25, 2014. A series of explosions killed 18 people at a Shi'ite political organisation's rally in Iraq on Friday, police and medical sources said. The militant group, Asaib Ahl Haq (League of the Righteous), introduced its candidates for elections on April 30 at the rally in eastern Baghdad. Three bombs exploded in succession as people were leaving, Reuters reporters at the scene said. (Photo by Thaier al-Sudani/Reuters)

Survivors Erika Brannock, left, and Rebekah Gregory DiMartino, embrace in their wheelchairs as they head to the finish line of the Boston Marathon Tribute Run in Boston, Saturday, April 19, 2014. (Photo by Elise Amendola/AP Photo)

Air Force members check their cell phones after protesting for a second day, as they rest at the headquarters of the National Association of Warrant Officers and Sergeants in La Paz, Bolivia, Wednesday, April 23, 2014. Hundreds of low ranking soldiers from Bolivia's Armed Forces marched for a second day against the military high command's dismissal of four of its leaders who defended their call for more career opportunities. The Ministry of Defense has threatened to discharge the soldiers who continue to protest. (Photo by Juan Karita/AP Photo)

An anti-riot policeman reaches to grab a protester as they are hit with a water cannon during a protest against the upcoming visit of U.S. President Barack Obama next week, in front of the U.S. embassy in Manila April 23, 2014. (Photo by Romeo Ranoco/Reuters)