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On Wednesday afternoon a police officer was stabbed and killed by an assailant outside the British Houses of Parliament.
A car also ploughed into a crowd of people on Westminster bridge, killing one woman and injuring many. Three French teenagers on a school trip to London were also badly injured in the attack.
At present, five are confirmed dead and 40 people have been injured.
For live updates please see the Independent's live blog.
For many, the events unfolded over social media.
The case was the same for many MPs in the chamber.
Heard gunshots. Now in @HouseofCommons Chamber. Building in lockdown. But I am safe as are all of my Westminster staff. — Andrew Stephenson MP (@Andrew Stephenson MP)
Heard gunfire but safe inside Parliament now. Saw brave Police Officers and security pulling public inside to safety — Stephen McPartland (@Stephen McPartland)
I was walking briskly to a vote when crowds of MPs rushed towards me saying that shots have been fired and shouts of 'get back'. — Michael Fabricant 🇬🇧 (@Michael Fabricant 🇬🇧)
I am now hiding in my PA's office watching the news. — Michael Fabricant 🇬🇧 (@Michael Fabricant 🇬🇧)
House in lockdown following shooting incident outside palace. All NW Hants team found and safe. — Kit Malthouse MP (@Kit Malthouse MP)
Just a quick message to confirm my staff and I are safe with colleagues in commons. Very concerned for those who have been attacked though. — Jessica Morden MP 💙 (@Jessica Morden MP 💙)
I am safe as are my staff. The police seem to have things under control. As always we are very grateful to @metpoliceuk. — Sir Edward Leigh MP (@Sir Edward Leigh MP)
Tom is fine and currently under lockdown in Parliament. Our thoughts are with those affected and their families. - Tom's team — Tom Brake (@Tom Brake)
in Berlin and seeing reports of what's happening in Westminster - desperately worried for all there and thinking of friends and colleagues. — stellacreasy (@stellacreasy)
Away from Parliament today.Our #Streatham team that work out of the Commons are all safe. Very much thinking of all there partic the injured — ChukaUmunna (@ChukaUmunna)
Hope everyone is safe. My team are all safe and accounted for. No idea what is happening so relying on BBC and Sky like everyone else. — Wes Streeting MP (@Wes Streeting MP)
Just heard horrific news from Westminster. Thoughts & prayers with injured & their families, our emergency services & those still locked in — Liz Kendall (@Liz Kendall)
Commons business cancelled for the day. Parliament still in lockdown. Thoughts with the police and security staff on duty. — Andy Slaughter (@Andy Slaughter)
Safe. Awaiting news. Heart goes out to those who have been attacked. Armed police securing building. — Caroline Flint (@Caroline Flint)
For the love of God @SkyNews can you please stop showing pictures of injured members of the public? There is no need for this whatever. — Gavin Newlands MP (@Gavin Newlands MP)
A heartfelt thank you to all those who keep us safe in Parliament. Thoughts & prayers with everyone affected by this incident in Westminster — Michael Dugher (@Michael Dugher)
Incident at WM. Police did great job at clearing everyone away. Now behind police cordon outside PCH. Thought with those affected. — Stuart Donaldson (@Stuart Donaldson)
Police and security staff have ensured many of us are safe in difft places round Parliamentary estate. Huge thanks. Awaiting further news. — Rt Hon Alistair Burt (@Rt Hon Alistair Burt)
Deeply shocking incident at Parliament. Thanks to all police & staff who responded so quickly. Thoughts & prayers with those injured — Baroness Nicky Morgan (@Baroness Nicky Morgan)
The admiration I have for the people who work here to keep us safe is boundless. I'm so sorry for them today — Jess Phillips MP (@Jess Phillips MP)
Not sure how appropriate it is for this @ScotParl debate to carry on given the shocking news from Westminster — Murdo Fraser (@Murdo Fraser)
Agreed. https://t.co/1Nn9VKttUO — Ruth Davidson (@Ruth Davidson)
I have left chamber. I can't understand how this debate can go on. At least a suspension would have shown some respect @ScotParl — Finlay Carson MSP (@Finlay Carson MSP)
Very pleased that sense has won the day & Holyrood has been suspended until we have a better understanding of what is going on in WM. — Ruth Davidson (@Ruth Davidson)
Parliament must not be cowered by this incident and I'd like the House of Commons to reconvene as soon as possible this afternoon. — Adam Afriyie (@Adam Afriyie)
@CommonsLeader Parliament needs to keep calm and carry on democracy and resume sitting asap — David Burrowes (@David Burrowes)
Commons public gallery now cleared. MPs to be evacuated last not sure if then back to normal or whether we're being moved somewhere else. — James Heappey MP (@James Heappey MP)
I disagree @SebastianEPayne we demonstrate our resistance by practicing our democratic traditions. — Tom Tugendhat (@Tom Tugendhat)
Bournemouth MP @Tobias_Ellwood helped injured policeman in Parliament - gave mouth-to-mouth. His brother was killed in Bali terrorist attack — Peter Henley (@Peter Henley)
Whoever has attacked our parliament for whatever motive will not succeed in dividing us. All of my thoughts with those injured. — Brendan Cox (@Brendan Cox)
For live updates, please see the Independent's live blog.
More: Westminster terror incident: What we know and what we don't know
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