London's Mayor has said it is too soon to draw conclusions, but I think it is looking more and more likely that this is a terrorist attack.
We have heard from a man - an attacker, who you see in the ITV News footgage - with a knife and blood on his hands, saying "...we swear by almighty Allah, that we will never stop fighting you. Until you leave us alone, your people will never be safe".
He goes on: "...the only reason we have done this is because Muslims are dying by British soldiers every day.
There have been very distressing scenes here at Woolwich earlier today. Now we have a massive police investigation, and the Prime Minister is flying home this evening.