People walk past the star of late blues legend B.B. King on the Walk of Fame in Los Angeles, California May 15, 2015. Blues legend B.B. King, who took his music from rural juke joints to the mainstream and inspired a generation of guitarists from Eric Clapton to Stevie Ray Vaughan, has died in Las Vegas. He was 89. (Photo by Mario Anzuoni/Reuters)

A bus is seen after overturning and falling into a valley in Chunhua county in Xianyang, Shaanxi province, China, May 16, 2015. At least 35 people were killed in the accident when the bus carrying 46 people plunged into a ravine on Friday, Xinhua News Agency reported. (Photo by Reuters/Stringer)

A bus is seen after overturning and falling into a valley in Chunhua county in Xianyang, Shaanxi province, China, May 16, 2015. (Photo by Reuters/Stringer)

Director George Miller (R) poses with cast members (from L-R) Nicholas Hoult, Rosie Huntington-Whiteley, Courtney Eaton, Charlize Theron, Tom Hardy, Zoe Kravitz and Abbey Lee during a press day for “Mad Max: Fury Road” in Los Angeles, California May 2, 2015. When director Miller returned to his dystopian “Mad Max” franchise after 30 years for “Fury Road”, he wanted to find a visceral way to immerse the audience in his surreal, saturated post-apocalyptic world. (Photo by Mario Anzuoni/Reuters)

Hirokatsu Hashimoto (L) of Japan jumps for a return next to his partner Noriyasu Hirata during their men's doubles match against Lee Yong-dae and Yoo Yeon-seong of South Korea at the semi-finals of the 2015 Sudirman Cup World Team Badminton Championships in Dongguan, Guangdong province, China, May 16, 2015. (Photo by Reuters/Stringer)

An Israeli soldier takes a position during clashes with Palestinian protesters following a protest marking Nakba Day near Israel's Hawra checkpoint near the West Bank city of Nablus May16, 2015. Palestinians marked “Nakba” (Catastrophe) on May 15 to commemorate the expulsion or fleeing of some 700,000 Palestinians from their homes in the war that led to the founding of Israel in 1948. (Photo by Abed Omar Qusini/Reuters)

Dancers take part in the “Musee de la Danse” choreographed by the French choreographer Boris Charmatz at the Tate Modern gallery in London, May 16, 2015. (Photo by Paul Hackett/Reuters)

Dancers take part in the “Musee de la Danse” choreographed by the French choreographer Boris Charmatz at the Tate Modern gallery in London, May 16, 2015. (Photo by Paul Hackett/Reuters)

Russian President Vladimir Putin takes part in a gala match of the National Amateur Ice Hockey Teams' Festival organised by the Night Ice Hockey League in Sochi, Russia, May 16, 2015. (Photo by Aleksey Nikolskyi/Reuters/RIA Novosti/Kremlin)

A fan of Russia waves flag during their Ice Hockey World Championship semifinal game against the U.S. at the O2 arena in Prague, Czech Republic May 16, 2015. (Photo by David W. Cerny/Reuters)

A woman walks with her Pomeranian dog during an international dog exhibition in Kannot, central Israel May 16, 2015. Some 800 purebred dogs from about 180 mini breeds participated in the exhibition. (Photo by Amir Cohen/Reuters)

A Belgian shepherd dog is seen during an international dog exhibition in Kannot, central Israel May 16, 2015. (Photo by Amir Cohen/Reuters)

Maltese dogs are seen on a table during an international dog exhibition in Kannot, central Israel May 16, 2015. (Photo by Amir Cohen/Reuters)

Tyeisha Gillyard (L), from the Overbrook School for the Blind and Esmeralda Chavez, from the New York Institute for Special Education, compete in the girls 75-yard dash during the annual Eastern Athletic Association for the Blind track and field tournament at the Perkins School for the Blind in Watertown, Massachusetts May 16, 2015. Blind runners hold on to handles on wires to guide them down the track and help them stay in their lane. Over 80 student athletes who are blind or visually impaired from five different schools for the blind in the eastern United States participated in the event. (Photo by Brian Snyder/Reuters)

Venezuela's President Nicolas Maduro drives a Yutong bus during the opening ceremony of a new avenue and the inauguration of a public transportation route in Los Teques, Venezuela May 16, 2015. (Photo by Marco Bello/Reuters)

Graduates arrive for commencement at University of California, Berkeley in Berkeley May 16, 2015. (Photo by Noah Berger/Reuters)

Protesters hold the national flag during a demonstration demanding the resignation of Guatemalan President Otto Perez Molina, in downtown Guatemala City, May 16, 2015. (Photo by Jorge Dan Lopez/Reuters)

Fans jump together from the fountain during the final day of the Rock in Rio USA concert in Las Vegas, Nevada May 16, 2015. (Photo by L. E. Baskow/Reuters)

A dancer performs on a glass ceiling during the show Claraboia (Skylight), a creation by Brazilian choreographer and dancer Morena Nascimento in Sao Paulo May 16, 2015. (Photo by Nacho Doce/Reuters)

A dancer performs on a glass ceiling during the show Claraboia (Skylight), a creation by Brazilian choreographer and dancer Morena Nascimento in Sao Paulo May 16, 2015. (Photo by Nacho Doce/Reuters)

Artists perform front of a giant screen showing Vietnam's late revolutionary leader Ho Chi Minh during a rehearsal for the ceremony to celebrate his birthday in Hanoi May 17, 2015. Vietnam marks the 125th birthday anniversary of Ho Chi Minh, the founder of modern Vietnam, on May 19. (Photo by Reuters/Kham)

Aisikaier Wubulikasimu, a 42-year-old Uighur acrobat, walks backwards on tightrope with his eyes covered by a red cloth, during a challenge in Kunming, Yunnan province, China, May 16, 2015. Aisikaier successfully completed the challenge on a 100-metre-long tightrope between two buildings about 150 metres above ground, local media reported. (Photo by Wong Campion/Reuters)

Aisikaier Wubulikasimu, a 42-year-old Uighur acrobat, walks backwards on tightrope with his eyes covered by a red cloth, during a challenge in Kunming, Yunnan province, China, May 16, 2015. (Photo by Wong Campion/Reuters)

Joss Stone performs during the final day of the Rock in Rio USA concert in Las Vegas, Nevada May 16, 2015. (Photo by L. E. Baskow/Reuters)

An Afghan policeman carries an injured boy from site of an attack in Kabul, Afghanistan May 17, 2015. A car bomb rammed a convoy of foreign troops near the main airport in Afghanistan's capital on Sunday, killing at least three civilians in the latest attack in the city, police and a witness said. (Photo by Mohammad Ismail/Reuters)

A group of fans dressed in homemade replica armours of “Avengers: Age of Ultron” movie characters, Iron Man, Captain America and Thor, watch the film in a theatre in Changchun, Jilin province, China, May 16, 2015. The group, led by college student Zu Bingqun, spent about 70,000 yuan to make the replica armours for all the main characters in the movie, local media reported. (Photo by Reuters/Stringer)

A Palestinian man holds a symbolic key as Hamas militants display a weapon during a rally after Nakba Day in Rafah in the southern Gaza Strip May 17, 2015. Palestinians mark “Nakba” (Catastrophe) on May 15 to commemorate the expulsion or fleeing of some 700,000 Palestinians from their homes in the war that led to the founding of Israel in 1948. (Photo by Ibraheem Abu Mustafa/Reuters)

A photographer takes picture of young surfers before the final of the men's World Surf League (WSL) Rio Pro championship in Rio de Janeiro May 17, 2015. (Photo by Sergio Moraes/Reuters)

U.S. Courtney Conlogue surfs to win the final of the World Surf League (WSL) Rio Pro championship in Rio de Janeiro, Brazil, Sunday, May 17, 2015. Conlogue defeated South Africa's Bianca Buitendag to win the championship. (Photo by Felipe Dana/AP Photo)

Brazil's Filipe Toledo surfs to win the final of the World Surf League (WSL) Rio Pro championship in Rio de Janeiro, Brazil, Sunday, May 17, 2015. Toledo defeated Australia's Bede Durbidge and won the championship. (Photo by Felipe Dana/AP Photo)

A man sells “Caipirinhas”, Brazil's national cocktail drink made with cachaca (sugar cane hard liquor), in the morning before the finals of the men's World Surf League (WSL) Rio Pro championship in Rio de Janeiro May 17, 2015. (Photo by Sergio Moraes/Reuters)

A Georgian serviceman takes part in the joint U.S.-Georgian exercise Noble Partner 2015 at the Vaziani training area outside Tbilisi, Georgia, May 17, 2015. (Photo by David Mdzinarishvili/Reuters)

A boy stands next to drums during a rally supporting Burundi's President Pierre Nkurunziza in Bujumbura, Burundi, May 17, 2015. President Nkurunziza makes his first public appearance in the capital Bujumbura since an attempted coup last week failed to oust him from power, saying he is monitoring a threat posed by Islamist militants from Somalia. (Photo by Goran Tomasevic/Reuters)

A supporter of Burundi's President Pierre Nkurunziza dance during a rally in Bujumbura, Burundi, May 17, 2015. (Photo by Goran Tomasevic/Reuters)

Bret Boko (3) and driver Ari Moilanen win the Finlandia Ajo trotting race at the Vermo horse track in Helsinki, Finland May 17, 2015. (Photo by Roni Rekomaa/Reuters/Lehtikuva)

Cheerleaders perform during the Ice Hockey World Championship third-place game between the Czech Republic and the U.S. at the O2 arena in Prague, Czech Republic May 17, 2015. (Photo by Laszlo Balogh/Reuters)

A Palestinian protester (R) gestures in front of an Israeli police officer near Damascus Gate outside Jerusalem's Old City during a march marking Jerusalem Day May 17, 2015. Israeli police on horseback confronted dozens of Palestinian protesters who threw stones at the forces protecting thousands of flag-waving Jewish nationalists marching on Sunday on the anniversary of Israel's capture of East Jerusalem in a 1967 war. Israel later annexed the area, making it a part of its capital in a move never recognised internationally. (Photo by Baz Ratner/Reuters)

A boy who has cancer poses for a picture while dressed as Superman before a charity run raising funds for the treatment of children with cancer at a children's hospital in Managua May 17, 2015. (Photo by Oswaldo Rivas/Reuters)

A girl who has cancer poses for a picture before a charity run raising funds for the treatment of children with cancer at the children's hospital in Managua May 17, 2015. (Photo by Oswaldo Rivas/Reuters)

Russia's Alexander Ovechkin (R) arrives before their Ice Hockey World Championship final game against Canada at the O2 arena in Prague, Czech Republic May 17, 2015. (Photo by Laszlo Balogh/Reuters)

Russia's goaltender Sergei Bobrovski reacts during their Ice Hockey World Championship final game against Canada at the O2 arena in Prague, Czech Republic May 17, 2015. (Photo by Andre Ringuette/Reuters)

Russia's players react after losing their Ice Hockey World Championship final game against Canada at the O2 arena in Prague, Czech Republic May 17, 2015. (Photo by Laszlo Balogh/Reuters)

Canada's goaltender Mike Smith holds the trophy during the victory ceremony of the Ice Hockey World Championship final game at the O2 arena in Prague, Czech Republic May 17, 2015. (Photo by David W. Cerny/Reuters)

Benfica's Salvio celebrates the league title at the end of their Portuguese premier league soccer match against Guimaraes at Afonso Henriques stadium in Guimaraes, Portugal May 17, 2015. (Photo by Miguel Vidal/Reuters)

Visitors take pictures during a tour organized by the Panama Canal to the expansion project in Panama City May 17, 2015. Panama Canal Authority hosted a general public tour of the new, expanded locks on the Pacific side of the Panama Canal. Visitors went inside the new locks before they will be filled with water. (Photo by Carlos Jasso/Reuters)

Mark Marczyk and Marichka Kudriavtseva participate in the “hora” during their Ukrainian-themed public wedding at Dufferin Grove Park in Toronto, May 17, 2015. The couple had met during the uprising in Kiev's Maidan square in January 2014. Kudriavtseva, from Ukraine, and Marczyk from Canada, wanted to have a public wedding in a Toronto park and invited the general public over social media to celebrate with them. (Photo by Mark Blinch/Reuters)

Colombia National Army soldiers, who were injured by mines, participate in the third sitting volleyball in Bello, municipality of Antioquia, Colombia May 17, 2015. According to the Mine Action Service of the United Nations, Colombia has the second highest number of landmine victims in the world, after Afghanistan. (Photo by Fredy Builes/Reuters)

A woman gets an African-Colombian hairstyle during the Afro-hairstyles XI Competition in Cali, Colombia May 17, 2015. (Photo by Jaime Saldarriaga/Reuters)

A three-storey nail house, the last building in the area, with a Chinese national flag on its rooftop is seen in the middle of a newly-built road in Luoyang, Henan province, China, May 16, 2015. According to local media, the house owner did not agree with government's compensation plan for relocation and refused to move out. (Photo by Reuters/Stringer)

A rebel fighter of the Al-Furqan brigade covers his ears as a fellow fighter fires a vehicle's weapon during what the rebels said is an offensive to take control of the al-Mastouma army base which is controlled by forces loyal to Syria's President Bashar al-Assad near Idlib city May 17, 2015. (Photo by Khalil Ashawi/Reuters)

A model wears a floral head dress as she promotes a chain of garden centres at the Royal Horticultural Soceity's Chelsea Flower Show in London, Britain, May 18, 2015. (Photo by Toby Melville/Reuters)

A visitor looks at a display of Lupins at the Royal Horticultural Soceity's Chelsea Flower Show in London, Britain, May 18, 2015. (Photo by Toby Melville/Reuters)

Three synchronized swimmers wear hats made out of 800 chrysanthemums each at the M & G Retreat garden at the Royal Horticultural Soceity's Chelsea Flower Show in London, Britain, May 18, 2015. (Photo by Toby Melville/Reuters)

A boy carries goods on top of his head near soldiers during a protest against Burundi President Pierre Nkurunziza and his bid for a third term in Bujumbura, Burundi, May 18, 2015. Small groups of protesters shouted slogans against Burundi President Pierre Nkurunziza and his bid for a third term in office on Monday, resuming street demonstrations days after he survived an attempted coup. (Photo by Goran Tomasevic/Reuters)