Senator Barack Obama (D-IL) (R) stands in front of Senator Hillary Clinton (D-NY) as they arrive for U.S. President George W. Bush's annual State of the Union speech to a joint session of Congress at the U.S. Capitol in Washington in this January 23, 2007 file photo. Hillary Clinton announced her second run for the presidency on April 12, 2015 starting her campaign as the Democrats' best hope of fending off a crowded field of lesser-known Republican rivals and retaining the White House. (Photo by Larry Downing/Reuters)

Women dance during the traditional Feria de Abril (April fair) in the Andalusian capital of Seville, southern Spain, April 21, 2015. The fair will run until April 26. (Photo by Marcelo del Pozo/Reuters)

A mass pillow fight in Trafalgar Square in central London on April 5, 2014 on International Pillow Fight Day. (Photo by Jane Scanlan)

An Airbus A380 aircraft prepares to land at Mumbai airport in this May 8, 2007 file photo. Sentiment at some of Asia's biggest firms deteriorated again in the fourth quarter, falling to a four-year low under the weight of concerns about slowing growth in China, the region's biggest economy, a Thomson Reuters/INSEAD survey showed. (Photo by Arko Datta/Reuters)

Indian school children wearing traditional Punjabi attire sit as they take part in the full and final dress rehearsal for India's Independence Day parade and celebrations in Amritsar, India, 13 August 2016. India's 70th Independence Day will be celebrated on 15 August, to commemorate its independence from British rule and its birth as a sovereign nation on that day in 1947. (Photo by Raminder Pal Singh/EPA)

A man pedals his cycle rickshaw during monsoon rains in New Delhi, India August 31, 2016. Normal life was thrown out of gear as heavy rainfall lashed the city Wednesday morning, resulting in waterlogging and traffic jams. (Photo by Cathal McNaughton/Reuters)

Police dog handlers wait outside the Loftus Road stadium after FA Cup Fourth Round between Queens Park Rangers and Chelsea on January 28, 2012 in London, England. Security has been stepped up after QPR player Anton Ferdinand recieved a package containing a bullet. (Photo by Dan Kitwood/Getty Images)

This Thursday, April 30, 2015 photo shows Lebanese citizens walking on the Corniche, or waterfront promenade in Beirut, Lebanon. This photo was shot through the lowered veil of a niqab, which is worn by some conservative Muslim women. The cloth allows women to follow a strict interpretation of their religious beliefs by preventing others from seeing their faces. (Photo by Hassan Ammar/AP Photo)