A woman dressed as the Star Trek character “Leeta” (C) and man dressed as “Rom” (2R) arrive to attend the “Destination Star Trek London” convention at the ExCeL centre on October 19, 2012 in London, England. The three-day convention, which opened to the general public today, will be attended by all five actors who played captains throughout the 46-year-old series. (Photo by Oli Scarff)

A policeman stands by a burning car, set alight during a communist march in the East End of London. (Photo by Topical Press Agency/Getty Images). Circa 1936

An Israeli policeman prevents a Palestinian man from entering the compound which houses al-Aqsa mosque, known by Muslims as the Noble Sanctuary and by Jews as the Temple Mount, in Jerusalem's Old City September 28, 2015. (Photo by Ammar Awad/Reuters)

Dancers perform on stage during Diwali celebrations in Leicester, Britain November 11, 2015. (Photo by Darren Staples/Reuters)

The "Skylanders Eruptor" balloon moves by people on balconies during the 89th Macy's Thanksgiving Day Parade in the Manhattan borough of New York, November 26, 2015. (Photo by Andrew Kelly/Reuters)

An Iraqi Muslim woman walks past Christmas decorations for sale in the Shiite holy city of Najaf on December 17, 2015. (Photo by Haidar Hamdani/AFP Photo)

Supporters and opponents of Russian opposition activist and anti-corruption crusader Alexei Navalny clash during unsanctioned protest in Manezhnaya Square in Moscow, Russia, Tuesday, December 30, 2014. The unsanctioned protest came hours after Alexei Navalny was found guilty of fraud and given a suspended sentence. Navalny, who has been under house arrest since February, is accused of breaking the terms of his house arrest to attend the rally and was detained by police as he approached the site of the protest. (Photo by Ivan Sekretarev/AP Photo)

A Kenyan soldier takes cover as shots are fired in front of Garissa University in Garissa town, located near the border with Somalia, some 370km northeast of the capital Nairobi, Kenya, 02 April 2015. At least 15 people have been killed and some 60 were injured in an attack carried out by Somalia's Islamist militant group al-Shabab, according to local media reports. (Photo by Dai Kurokawa/EPA)