Amended subject.
"A man was shouting 'knife, knife, knife' and a man was brought down by taser".
BBC News. On twitter, apparently.
Reportedly contained and "not ongoing".
edit:
A man arrested near one of the gates to Parliament for possession of a knife. No indication that he was attempting to do anything with it, necessarily...
http://www.bbc.co.uk/news/uk-40303300A man has been detained by armed police outside the Palace of Westminster.
A bearded man, wearing black trousers and a grey sweatshirt, was seen being held against the fence with his arms behind his back by a police officer.
The incident is not thought to be terror related. The Carriage Gates entrance to Parliament is closed.
Joe Murphy, political editor of the Evening Standard, tweeted that there were shouts of "knife knife knife" and a man was brought down with a Taser.
