British counter-terrorism police officers carry their weapons as they work on Westminster Bridge, adjacent to the Houses of Parliament in central London on March 22, 2017, during an emergency incident. British police shot a suspected attacker outside the Houses of Parliament in London on Wednesday after an officer was stabbed in what police said was a "terrorist" incident. One woman has died and others have "catastrophic" injuries following a suspected terror attack outside the British parliament, local media reported on Wednesday citing a junior doctor. / AFP PHOTO / Daniel LEAL-OLIVAS (Photo credit should read DANIEL LEAL-OLIVAS/AFP/Getty Images)
