LONDON, ENGLAND - MARCH 22: Police take security measures around the Houses of Parliament on March 22, 2017 in London, England. At least one man was shot dead by police outside the U.K. parliament Wednesday afternoon after stabbing a police officer, said Commons Leader David Lidington. Parliament Square is under a complete security lockdown with all entrances and exits suspended, with all roads into the square cordoned off by police. (Photo by Inci Gundag/Anadolu Agency/Getty Images)
