Statement from the Mayor of London, Sadiq Khan:
Today London suffered a horrific attack near Parliament Square which we are treating as a terrorist attack.
A number of people have lost their lives and at least twenty people have been injured.
My heart goes out to those who have lost loved ones and to everyone who has been affected.
Tragically, a Metropolitan Police officer who was doing his duty protecting our city is amongst those who have been killed – and my thoughts are with his family this evening.
I want to express my gratitude on behalf of all Londoners to the police and emergency services who have shown tremendous bravery in exceptionally difficult circumstances.
I have spoken to the Acting Metropolitan Police Commissioner Craig Mackey, and national lead for Counter-Terrorism Policing and Acting Deputy Commissioner Mark Rowley – and remain in close contact with them.
Londoners should be aware that there will be additional armed and unarmed police officers on our streets from tonight in order to keep Londoners and all those visiting our city safe.
I want to reassure all Londoners and all our visitors not to be alarmed – our city remains one of the safest in the world.
London is the greatest city in the world and we stand together in the face of those who seek to harm us and destroy our way of life. We always have, and we always will.
Londoners will never be cowed by terrorism.