Residents of the Brussels suburb of Molenbeek are searched by police before taking part in a memorial gathering to honour the victims of the recent deadly Paris attacks, in Brussels, Belgium, November 18, 2015. (Photo by Yves Herman/Reuters)

People ride a motorcycle near Koudoukou Mosque where Pope Francis meets Imam Tidiani Moussa Naibi in Bangui, Central African Republic, November 30, 2015. (Photo by Stefano Rellandini/Reuters)

A small section of the expanding remains of the Veil Nebula, a massive star that exploded about 8,000 years ago. The entire nebula is 110 light-years across, covering six full moons on the sky as seen from Earth, and resides about 2,100 light-years away in the constellation Cygnus, the Swan. Image taken by NASA's Hubble Space Telescope. Released September 24, 2015. (Photo by Reuters/NASA/ESA/Hubble Heritage Team)

Activists stage a protest outside the Louvre pyramid, calling the museum to cancel its contracts with French oil giant Total and Italian oil company Eni, in Paris, France, December 9, 2015, as the World Climate Change Conference 2015 (COP21) continues at Le Bourget near the French capital. (Photo by Benoit Tessier/Reuters)

A photo provided by the Atlanta Journal-Constitution shows Atlanta police officer T. R. Coxe removing painted material of a large swastika featuring a likeness of Republican presidential candidate, Donald Trump, along the northbound Buford Highway Connector just south of the Piedmont exit, in Atlanta, Georgia, USA, 09 December 2015. Just days after Donald Trump's call to ban Muslims from entering the United States, someone painted large swastikas featuring the Republican presidential candidate's face on at least two northeast Atlanta bridge supports. The symbol, which includes a cartoon of Trump sporting a Hitler-like mustache, was painted along the Buford Highway Connector. A second, similar image was found on a concrete bridge support on nearby Piedmont Road. Trump said in a statement released on 07 December that there should be a total and complete shutdown of Muslims entering the United States. (Photo by John Spink/EPA/AJC)

A receptionist dinosaur robot performs at the new robot hotel, aptly called Henn na Hotel or Weird Hotel, in Sasebo, southwestern Japan, Wednesday, July 15, 2015. From the receptionist that does the check-in and check-out to the porter that’s a stand-on-wheels taking luggage up to the room, the hotel, that is run as part of Huis Ten Bosch amusement park, is “manned” almost totally by robots to save labor costs. (Photo by Shizuo Kambayashi/AP Photo)

Muslim children play sack race during Eid-al-Fitr celebration in Taguig city, south of Manila July 18, 2015. (Photo by Romeo Ranoco/Reuters)

A beluga whale sprays water towards visitors during a summer attraction at the Hakkeijima Sea Paradise aquarium in Yokohama, suburban Tokyo on July 20, 2015. Tokyo's temperature climbed over 34 degree Celsius on July 20, one day after the end of the rainy season. (Photo by Toshifumi Kitamura/AFP Photo)