A priest speaks through a megaphone to riot police and anti-government protesters at the site of recent clashes in Kiev, in this February 12, 2014 file photo. (Photo by Konstantin Chernichkin/Reuters)

A flock of starlings fly over an agricultural field near the southern Israeli city of Netivot, in this February 12, 2014 file photo. (Photo by Amir Cohen/Reuters)

A demonstrator jumps on a shield wall formed by riot police during a protest against the government of Venezuela's President Nicolas Maduro, in Caracas, in this February 12, 2014 file photo. (Photo by Carlos Garcia Rawlins/Reuters)

People work on the Olympic rings during heavy snow at the Laura Cross-country Ski and Biathlon Centre in Krasnaya Polyana near Sochi, in this January 24, 2014 file photo. (Photo by Alexander Demianchuk/Reuters)

A man holds a baby saved from under rubble, who survived what activists say was an air strike by forces loyal to Syrian President Bashar al-Assad, in Masaken Hanano in Aleppo, in this February 14, 2014 file photo. (Photo by Hosam Katan/Reuters)

Interior Ministry members detain a man during a protest rally held by opposition activists and members of the Other Russia movement in St. Petersburg, in this February 15, 2014 file photo. (Photo by Maxim Zmeyev/Reuters)

A fire-fighter works to extinguish a fire which broke out on piles of reeds at a paper factory in Changde, Hunan province, in this February 16, 2014 file photo. (Photo by Reuters/Stringer)

Anti-government protesters attack a man (C) whom they suspect of being a sniper who shot people during recent clashes, in central Kiev, in this February 22, 2014 file photo. (Photo by Baz Ratner/Reuters)

Russia's President Vladimir Putin (C), Prime Minister Dmitry Medvedev (R) and International Olympic Committee (IOC) President Thomas Bach of Germany check their watches before the closing ceremony of the 2014 Sochi Winter Olympics, in this February 23, 2014 file photo. (Photo by Dmitry Astakhov/Reuters/RIA Novosti)

The body of one of the siblings killed in a bomb blast near an anti-government protest site on Sunday is prepared for a funeral at a Buddhist temple in Bangkok, in this February 24, 2014 file photo. (Photo by Athit Perawongmetha/Reuters)

A Central African Army (FACA) soldier stabs the corpse of a man, who was killed after he was accused of joining the ousted Seleka fighters, in the capital Bangui, in this February 5, 2014 file photo. (Photo by Siegfried Modola/Reuters)

An Afghan National Army (ANA) soldier is seen through damaged glass as he keeps watch at the Forward Base in Nari district near the army outpost in Kunar province, in this February 24, 2014 file photo. (Photo by Omar Sobhani/Reuters)

Toronto's Chief Budget Officer Councillor Frank Di Giorgio (L) shares a moment with Toronto Mayor Rob Ford during a budget meeting at City Hall in Toronto, in this January 30, 2014 file photo. (Photo by Aaron Harris/Reuters)

Belarus' Anton Kushnir competes during the men's freestyle skiing aerials qualification round at the 2014 Sochi Winter Olympic Games in Rosa Khutor, in this February 17, 2014 file photo. (Photo by Dylan Martinez/Reuters)

Britain's Prince Charles, wearing traditional Saudi attire, attends a traditional Saudi dance, known as “Arda”, which was performed during the Janadriya cultural festival at Der'iya in Riyadh, in this February 18, 2014 file photo. (Photo by Fayez Nureldine/Reuters)

Ultra-orthodox Jewish bride Rivka Hannah Krois watches her groom dance after their traditional wedding ceremony in the Mea Shearim neighbourhood of Jerusalem, in this February 19, 2014 file photo. (Photo by Ronen Zvulun/Reuters)

An interior view shows the house of Ukraine's former prosecutor general Viktor Pshonka with a painting of Pshonka and former Ukrainian president Viktor Yanukovich, in the village of Gorenichy outside Kiev, in this February 24, 2014 file photo. (Photo by Konstantin Chernichkin/Reuters)

An aerial view shows waves breaking against a Spanish cargo ship carrying fertiliser, which has broken in two, off the beach in Anglet on the Atlantic coast of France, in this February 5, 2014 file photo. (Photo by Regis Duvignau/Reuters)

An anti-government protester stands near Thai soldiers guarding a Defence Ministry compound, which is serving as a temporary office for Thai Prime Minister Yingluck Shinawatra, in north Bangkok, in this February 19, 2014 file photo. (Photo by Athit Perawongmetha/Reuters)

An aerial view shows Independence Square during clashes between anti-government protesters and Interior Ministry members and riot police, in central Kiev, in this February 19, 2014 file photo. (Photo by Olga Yakimovich/Reuters)

A woman reacts as anti-government protesters place a dead body on a stretcher after violence erupted in the Independence Square in Kiev, in this February 20, 2014 file photo. (Photo by Vasily Fedosenko/Reuters)

Troops hold coloured cards during a military parade celebrating Independence Day at Zocalo square in downtown Mexico City, in this September 16, 2014 file photo. (Photo by Edgard Garrido/Reuters)

A radical protester clashes with law enforcement members on the Day of Ukrainian Cossacks, marked by activists and supporters of the All-Ukrainian Union Svoboda (Freedom) Party and far-right activists and nationalists to honour the role of the movement in the history of Ukraine, during a rally near the parliament building in Kiev, in this October 14, 2014 file photo. (Photo by Gleb Garanich/Reuters)

A snow-covered field is seen near Buffalo, New York, in this November 21, 2014 file photo. (Photo by Lindsay DeDario/Reuters)

A protester stands with his hands on his head as a cloud of tear gas approaches after a grand jury returned no indictment in the shooting of Michael Brown in Ferguson, Missouri, in this November 24, 2014 file photo. (Photo by Adrees Latif/Reuters)