Report by ITV News correspondent Emma Murphy
Tributes have been paid across the UK to the victims of the terrorist attack on Westminster bridge.
Thousands of people who had gathered in Parliament Square for a pro-Europe rally fell silent as Big Ben chimed to honour those who were killed and injured in Wednesday's attack.
As well as protesting Brexit ahead of Theresa May triggering Article 50 on 29 March, the Unite for Europe march was seen as an act of defiance against terrorism.
Opening the event, Alastair Campbell said: "Before we talk about Brexit, before we call on any of the speakers, we need to recognise that something really bad happened not far from here just the other day."
A minute's silence was also held before football matches across the country.
Members of the Muslim community in Birmingham gathered to condemn the attack by British-born Khalid Masood.
"For too long now, terrorists have been trying to define us, trying to represent us," rally organiser Waqar Azmi told ITV News.
"And what we want to say is that they do not represent us, they do not define us."
Police are continuing to piece together the details of Masood's past to get a picture of how he was radicalised and who he may have been associated with.
His phone data is being studied, including a WhatsApp message sent moments before he began the attack.
It has also emerged that Masood was cleared of attempted murder after a knife attack 15 years ago.