Pic via Ali Martin

Scores of armed police on the scene outside parliament where a man has been detained at gunpoint.

One male detained by armed police outside Carriage Gates, Parliament, eyewitness, taser was discharged pic.twitter.com/GuNSeMrcGH — Ross Kempsell (@rosskempsell) June 16, 2017

Suspect led into van:

NEW: One male suspect led away to custody van by police outside Parliament’s Carriage Gates #Westminster pic.twitter.com/PGQZGkvvQd — Ross Kempsell (@rosskempsell) June 16, 2017

Close-up photo of the suspect:

The Met say a man in his thirties has been arrested for possession of a knife. There are no reports of any injuries.