Defiant British lawmakers returned to parliament Thursday but outside, the forensic work and eerie absence of people and traffic at one of London's most popular tourist spots was a poignant reminder of the previous day's terror.
MPs and peers, aides, staff and journalists returned to work a day after a police officer was killed and his assailant shot dead on the cobbled yard of the Palace of Westminster in an attack claimed by the Islamic State group.
The House of Commons chamber was packed for the minute's silence in tribute to the victims, before MPs held a planned session on international trade, insisting it was "business as usual".
But just outside, forensic officers worked in a blue tent at the scene of the attack, before later combing the ground in a fingertip search for evidence.
At a location normally characterised by noisy traffic and hoards of tourists coming to see the world-famous building, the streets were silent.
Westminster's Underground station was closed, while Parliament Square, Westminster Abbey and adjoining roads were cordoned off -- although Westminster Bridge re-opened around lunchtime.
Parliament was locked down for several hours after the attack, in which the suspect rammed his car into crowds of people on the bridge, leaving two members of the public dead and dozens injured.
He then stabbed a diplomatic protection officer, Keith Palmer, on New Palace Yard just inside parliament's gates, before being shot dead by police.
Prime Minister Theresa May had been working not far from the scene, but was swiftly driven away.
On Thursday, she returned to the Commons to update MPs on the investigation and led tributes to the victims and the emergency services.
Foreign Office minister Tobias Ellwood stood at the back of the chamber as colleagues thanked him for his "heroic" effort in trying to resuscitate Palmer.
Early on Thursday, a bloodied rag was the only remnant left of the frantic efforts to save the policeman, a 48-year-old husband and father.
"This country will not be cowed," May said, watched from the Commons gallery by French Foreign Minister Jean-Marc Ayrault, who was in London to visit three French schoolchildren hurt in the attack.
Conservative MP James Cleverly was in tears as he paid tribute to the murdered policeman, with whom he had previously served in the army.
Labour MP Harriet Harman meanwhile echoed the views of many, when she said: "As an act of terror, it has failed because we are here and we are going to go about our business."
- 'Air of nervousness' -
A bouquet of flowers lay next to the security cordon outside Westminster Abbey as a tribute to the victims, while a single bloom was tucked into the knot of a police tape.
Flags on government buildings around Westminster flew at half-mast, but many people walked or cycled into work as usual.
"There's definitely an air of nervousness, you can feel that. It's very obvious to see that something very serious happened here," said Jason Llewelyn, a civil servant.
Staff were initially escorted into parliament through a side entrance and the House of Lords coatroom, although a larger entrance was later opened and visitors were also allowed in.
Tourists milled around the edge of the cordon, some taking photographs on their smartphones.
Stephanie Scheider, a 20-year-old nurse from Germany, took pictures in front of parliament's famous Big Ben clock tower, but expressed concern at the security situation.
"We won't go to Buckingham Palace because we feel not safe there but it's the only place we will avoid," she told AFP.
Queen Elizabeth II was due to visit a new police headquarters next to parliament on Thursday, but postponed the engagement.
Jemma Jackson, a paediatric nurse heading to work nearby, said: "I think it's right that we continue to carry on.
"I think people probably feel there is an element of fear, but really, we won't let this beat us."