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.
ITV News has uncovered a video showing Woolwich suspect Michael Adebolajo speaking at a demonstration at Harrow Central Mosque in 2009.
Documents suggest Security Services were trying to recruit Woolwich suspect Michael Adebolajo and had also approached members of his family.
Police in Kenya say they did everything they could to highlight their concerns about Michael Adebolajo.