The has been an incident on Whitehall – eyewitnesses say a man was tackled by several policemen and handcuffed and that there is a knife on the ground. No one has been injured and one man has been arrested. Armed police have blocked off the area. More as we get it…

A bag and what appears to be at least one knife on the ground, being photographed by forensic officers. Man arrested for possession of weapons.

The arrest (pic via @312dev):

Police questioning man at the scene:

#whitehall – police questioning man pic.twitter.com/WHb5Vt6bV9

— Angus Walker (@anguswalkertalk) April 27, 2017

Hooded man put into back of police car by armed police:

VIDEO: Man arrested with knives on Whitehall being put into unmarked police car outside the Treasury, Met helicopter overhead @LBC pic.twitter.com/wJVeXwcM1d

— Vincent McAviney (@Vinny_LBC) April 27, 2017

UPDATE: Statement from the Met:

A man has been arrested in Whitehall this afternoon, at approximately 14:22, following a stop and search as part of an ongoing operation. The man was arrested in Parliament Street, junction with Parliament Square, by armed officers from the Met’s Specialist Firearms Command. The man, aged in his late twenties, was arrested on suspicion of possession of an offensive weapon and on suspicion of the commission, preparation and instigation of acts of terrorism.Knives have been recovered from him. He is being detained under the Terrorism Act and is in custody in a south London police station. Detectives from the Counter Terrorism Command are continuing their investigation, and as a result of this arrest there is no immediate known threat.

The suspect: