A demonstrator catches fire after the gas tank of a police motorbike exploded during clashes in a protest against Venezuelan President Nicolas Maduro, in Caracas, Venezuela, May 3, 2017. Juan Barreto/AFP/Getty Images

A Hasidic Jewish pilgrim attends a commemoration of the anniversary of the death of Grand Rabbi Yeshaya Steiner, the founder of a famous Hasidic dynasty, in the village of Bodrogkeresztur, Hungary, April 29, 2017. Laszlo Balogh/Reuters

Workers and wine growers light heaters to protect vineyards from frost damage outside Chablis, France, April 28, 2017. Christian Hartmann/Reuters

Katy Perry arrives on the red carpet for the Metropolitan Museum of Art Costume Institute's benefit celebrating the opening of the exhibit 'Rei Kawakubo/Comme des Garcons: Art of the In-Between' in New York, May 1, 2017. The exhibit will be on view at the Metropolitan Museum of Art's Costume Institute from May 4 to September 4. Justin Lane/EPA

Supporters wait for President Donald Trump to deliver remarks at the National Rifle Association (NRA) Leadership Forum at the Georgia World Congress Center in Atlanta, April 28, 2017. Jonathan Ernst/Reuters

Mosul residents reach out for freshly baked cookies at a food distribution point inside western Mosul, Iraq, May 2, 2017. Thousands of people still live in the western part of the city where food is getting scarce due to fighting between Iraqi forces and the ISIS. Bram Janssen/AP Photo

Israeli children play on an army tank displayed by the Israeli military as part of Independence Day celebrations, in Givatayim, near Tel Aviv, May 2, 2017. Israel is celebrating 69 years since the modern Jewish state was formed. Ariel Schalit/AP Photo

Parkour coach Ibrahim al-Kadiri, 19, and Muhannad al-Kadiri, 18, demonstrate their Parkour skills amid damaged buildings in the rebel-held city of Inkhil, west of Deraa, Syria, April 7, 2017. Ibrahim discovered Parkour in Jordan, where he had fled to escape the war. Back in his home town since 2015, he now leads a group of 15 practitioners. Alaa Al-Faqir/Reuters

Girls dressed as witches take part in the Walpurgis Night celebrations on the medieval Charles Bridge in Prague, Czech Republic, April 30, 2017. According to Czech legend, the festival is associated with a witches' carnival and involves witches meeting with the devil for one final night of revelry before being consigned to the underworld. Martin Divisek/EPA

A boy on his father's shoulders looks around as people flock into the Real Maestranza bullring and pass large bullfight posters while crowding into the ring to take their seats before the start of the bullfight in Seville, Spain in the Feria de Abril. Jim Hollander/EPA

A woman lies in the street as protesters and police clash during a strike in Rio de Janeiro, Brazil, April 28, 2017. Throughout the country, unions backed by various social movements and indigenous tribes are striking against pension and labor reforms being pushed by the conservative government of President Michel Temer. Antonio Lacerda/EPA

A customer of the Hamal Alil sulphur spa gets a scrub and massage south of Mosul, Iraq, April 27, 2017. Many Iraqi soldiers visit the spa in between fighting against the ISIS for relaxation. Bram Janssen/AP Photo