A police officer places flowers from members of the public in London.(Will Oliver / EPA)
Union flags fly at half-staff in front of Big Ben at the Houses of Parliament in central London.(Niklas Halle’n / AFP/Getty Images)
Police forensics teams search Parliament Square outside the Houses of Parliament in London.(Andy Rain / EPA)
Pedestrians cross Westminster Bridge in the shadow of the Houses of Parliament in London after the bridge reopened following the March 22 terror attack.(Niklas Halle’n / AFP/Getty Images)
Police stand guard outside a flat in Birmingham, which was raided by anti-terror police in connection with the London attacks.(Christopher Furlong / Getty Images)
The front pages of U.K. daily newspapers reporting on the terror attack in central London.(Daniel Sorabji / AFP/Getty Images)
A member of the public is treated by emergency services near Westminster Bridge and the Houses of Parliament in London following a terror attack.(Carl Court / Getty Images)
Emergency services at the scene outside the Palace of Westminster in London. Police say they are treating a gun and knife incident at Britain’s Parliament “as a terrorist incident until we know otherwise.”(Stefan Rousseau / Associated Press)
Armed police following major incidents outside the Houses of Parliament in London.(ANDY RAIN / EPA)
Emergency services transport an injured person to an ambulance, close to the Houses of Parliament in London.(Matt Dunham / Associated Press)
In this image taken from video show police officers gather around a car adjacent to Houses of Parliament in London.(Associated Press)
A member of the public is treated by emergency services near Westminster Bridge and the Houses of Parliament in London.(Carl Court / Getty Images)
Emergency services at the scene outside the Palace of Westminster in London.(Stefan Rousseau / Associated Press)
Armed police in position outside the Houses of Parliament in London.(Andy Rain / EPA)
An iinjured man on London’s Westminster Bridge holds his knee in an image from video.(Radosaw Sikorski / AFP/Getty Images)
An injured man is helped to safety near Westminster Bridge in London.(Carl Court / Getty Images)
Bystanders look on outside the police security perimeter near the Houses of Parliament.(Jack Taylor / Getty Images)
An injured person is loaded into an ambulance near Westminster Bridge in London.(Carl Court / Getty Images)
A police officer directs pedestrians back from the area around the Houses of Parliament in London.(Andy Rain / EPA)
Police secure the area close to the Houses of Parliament in London.(Matt Dunham / Associated Press)
Armed police on a street outside the Houses of Parliament in London.(Andy Rain / EPA)
Police in London secure the area on the south side of Westminster Bridge close to the Houses of Parliament on Wednesday.(Matt Dunham / Associated Press)
Police in London close the area near Houses of Parliament on Wednesday after reports of violence.(Victoria Jones / Associated Press)
A police officer stands on Parliament Square outside of the Houses of Parliament in London on Wednesday after witnesses reported sounds like gunfire outside.(Kirsty Wigglesworth / Associated Press)
A lone assailant struck at the heart of London on Wednesday, mowing down pedestrians with a car and then fatally stabbing a police officer outside Britain’s Houses of Parliament in an apparent terrorist attack that took place on the anniversary of twin bombings in Brussels.
Four people were reported dead in the attack, including the police officer and the assailant, and dozens were injured. Tobias Ellwood, the Foreign and Commonwealth Office minister, had administered CPR to the officer as he lay on the sidewalk, but it was ultimately not enough.
Prime Minister Theresa May was at Parliament at the time and was rushed away in the back of a silver Jaguar. Speaking to journalists later outside her residence at 10 Downing St., May condemned what she described as “a sick and depraved terrorist attack.”
“The location of this attack was no accident,” she said. “These streets of Westminster — home to the world’s oldest Parliament — are engrained with a spirit of freedom that echoes in some of the furthest corners of the globe. And the values our Parliament represents — democracy, freedom, human rights, the rule of law — command the admiration and respect of free people everywhere.”
May pledged that lawmakers would meet Thursday and Londoners would go about their day as usual, “never giving in to terror and never allowing the voices of hate and evil to drive us apart.”
Mark Rowley, acting deputy commissioner at London’s Metropolitan Police, told reporters Wednesday that it appeared there was only one attacker, “but it would be foolish to be overconfident early on.”
Rowley declined to identify the attacker but said authorities believe they know who he was, and the working assumption is that he was inspired by “Islamist-related terrorism.”
Police raided six addresses overnight, resulting in eight arrests.
On Thursday, Rowley revised the death toll from five to four: the attacker, the police officer and two civilians. At total of 29 people required hospitalization, he said, and seven of them were in critical condition.
Authorities were still working out the number of “walking wounded.” Police had previously given the number of injured as around 40.