Still ongoing at time of posting..http://metro.co.uk/2017/06/16/man-held-at-gunpoint-by-police-outside-houses-of-parliament-in-ongoing-incident-6713279/
A man has been detained by armed police officers at the gates of the House of Commons.
Pictures from the scene show the man being pinned to the ground by police officers and Parliament has been put into lockdown. The carriage gates have been closed.
Reports from the scene suggested that armed officers ran from the grounds of parliament and that the man had been tasered. It is also being reported that they shouted ‘knife, knife, knife.’
Scotland Yard confirmed that a man in his 30s had been arrested on suspicion of possession of a knife at the Palace of Westminster.
Michael Crick from Channel 4 News said that police had picked up items on the floor, believed to be keys, a belt and a mobile phone, but a black square object remained on the ground.