published Mar 22nd 2017, 4:14 pm, by Thomas Penny, Tim Ross and Robert Hutton

(Bloomberg) —
London’s worst terror attack in more than a decade left four people dead, including the assailant and the police officer he stabbed, and at least 20 injured.

The attack shut down Parliament, leaving hundreds of lawmakers and workers in lockdown for several hours. Prime Minister Theresa May was in the lobby of the House of Commons before she was whisked to safety in a Jaguar. She made a statement just before 9 p.m. after chairing an emergency security meeting.

“The location of this attack was no accident,” she said, dressed in black with a quavering voice, outside her residence, a 10-minute walk from the attack. “The terrorists chose to strike at the heart of our capital city.”

A car crashed into a fence outside Parliament after running down pedestrians on Westminster Bridge. A man with a knife then ran through the gate and through security, assaulted an unarmed policeman and was shot. Among the dead were two people on the bridge. Three French school children were among those hurt.

“This is a day we planned for but hoped would never happen, sadly it’s now a reality,” Mark Rowley, national head of counter terrorism policing, told reporters. “We will continue to do all we can to protect the people of London.”

He said he “was satisfied” that there was just one attacker, who has yet to be identified and no group has claimed responsibility.

The BBC reported that the police officer who was killed passed away while being given mouth-to-mouth. Minister Tobias Ellwood was shown at the scene trying to resuscitate him. Grant Shapps, a Conservative lawmaker, tweeted that he was walking to the lower house to vote when he heard four gunshots and police ordered members of parliament to crawl to cover.

“Bang, Bang, Bang”

Tawhid Tanim, 28, a sales assistant who works near Parliament, described how he heard three gunshots and was told to run by police. “All I could hear was loud shots, gun shots – bang, bang, bang. People started running away. I could see a car had smashed the wall of Parliament,” he said. “Police were saying ‘move, move.”’

The attack adds to the sense of turmoil in the U.K., where political instability is already growing amid plans to start withdrawing from the European Union next week. It’s London’s biggest terrorist attack since the multiple bombing of the transport network in 2005, and strikes a symbolic — and highly fortified — site in the center of London.

The Metropolitan Police said about an hour after the attacks were reported at 2:40 p.m. that they are treating it as a “terrorist incident until we know otherwise.” Images aired by Sky News and the BBC showed people on the bridge and on the sidewalk near Parliament lying on the ground being treated by medical staff. One person was reported in the river.

It’s exactly a year since the worst terror attack in Belgium’s history, in which 32 people were killed and hundreds more were wounded at the Brussels airport and Maalbeek metro station, and a day after the U.K. joined the U.S. in unveiling new security measures banning laptops and iPads from flights from some Middle Eastern countries.

2005 Flashback

The U.K.’s last major terrorist attack was in July 2005, when four radical Islamists targeted morning rush hour, killing 52 civilians. More recently, in June 2016, Labour lawmaker Jo Cox was killed by a right-wing extremist, while in May 2013 a British soldier was stabbed to death outside his southwest London barracks by two men.

British police have arrested record numbers on suspected terrorist charges since the country’s terror threat was raised to its second-highest level in August 2014. Rowley said extra police officers, both armed and not, will roam the streets of London and the army will be called upon if needed.

May struck a defiant tone in addressing the country, urging people to carry on.

“Tomorrow morning Parliament will meet as normal; we will come together as normal; and Londoners and others from around the world who have come here to visit this great city will get up and go about their day as normal,” she said. “They will board their trains, they will leave their hotels, they will walk these streets, they will live their lives, and we will all move forward together, never giving in to terror.”