A worshipper wearing a kerchief with the image of the Our Lady of Fatima attends a mass at the Our Lady of Fatima shrine, in Fatima, central Portugal, Wednesday, May 13, 2015. Every year on May 12 and 13 tens of thousands of Catholic believers go on pilgrimage to the Fatima sanctuary to pray and attend masses where the apparitions of the Virgin Mary were witnessed by three shepherd children Lucia, Jacinta and Francisco in 1917. (Photo by Francisco Seco/AP Photo)

A model wears a floral headdress at the Royal Horticultural Society's Chelsea Flower show in London, Britain, May 22, 2017. The prestigious Chelsea Flower Show, held annually since 1913 in the Royal Hospital Chelsea grounds, is open to the public from the 23rd to the 27th of May, 2017. (Photo by Dylan Martinez/Reuters)

Police detain a protester during a demonstration against the recent gang-rape of a woman in a moving car, according to local media, in Kolkata, India May 31, 2016. A woman was kidnapped and gang-raped by at least four men on May 29 in the Salt Lake area of the city and is currently being treated in hopsital, local media reported. (Photo by Rupak De Chowdhuri/Reuters)

An army tank fires during a firefight against militants linked to al Qaeda near the southern Yemeni city of Zinjibar May 30, 2012. (Photo by Reuters/Yemen's Defence Ministry)

A supporter of BJP dances during celebrations after learning of initial poll results outside the party headquarters in New Delhi, on May 16, 2014. (Photo by Anindito Mukherjee/Reuters)

A man carries a block of ice left behind by a hailstorm in Sao Paulo, Brazil, on May 19, 2014. After the severe overnight hailstorm a layer of hailstones as deep as 20 centimeters covered streets and parks, drawing people to make snowmen and play in the ice, an unusual scene to the city. (Photo by Nelson Antoine/AP Photo)

A grave cleaner holds up a skull during exhumation works at the Cemetery General in Guatemala City May 24, 2013. If a lease on a grave has expired or not been paid, grave cleaners will break open the crypts to remove and rebury the bodies. (Photo by Jorge Dan Lopez/Reuters)

A view of an installation as part of the “S.A.C.R.E.D” exhibition by Chinese artist Ai Weiwei during the 55th La Biennale of Venice, in the church of Sant'Antonin in Venice May 28, 2013. (Photo by Stefano Rellandini/Reuters)