I'm here at Westminster Bridge where a man armed with a car and two knives, yesterday, carried out the UK's worst terror attack in more than a decade. Now we have new details to report. We now know that the attacker was British-born and had been previously investigated by the country's security services. He has been described as a lone wolf and inspired by Islamic terrorism.
That investigation will continue today overnight. Police carried out raids in London and Birmingham. Now behind me to the side here is St. Thomas Hospital, where many of the victims were brought. We're told that 29 people were treated, seven people remain in critical condition. Altogether four people were killed in the attack, including the attacker.
Behind me you'll see the parliament. MPs have gone back to work today but it's hardly business as usual. Much of this area here has been closed off and locked down. There's a very heavy police presence. There are helicopters whirring above and police boats patrolling the Thames.
I'm told that there is a debate now about reviewing security in Westminster. Officials obviously want to ensure that another attack like this cannot happen again. At the same time, they're mindful of not wanting to turn the symbol of British democracy into a sort of prison.
All around this area today there are tourists, there are people who are obviously quite surprised, still absorbing what's happened. Many of the tourists I've seen- some from South Korea, some from Spain- surprisingly, indicated that they weren't frightened by the events. They were obviously saddened. But a sense that they had become used to this sort of thing now. This is Joshua Chaffin for the Financial Times in London.