shots fired near parliment uk london.

LONDON — The knife-wielding terrorist who killed an American tourist and two others outside the U.K. Parliament was British-born and previously investigated for "violent extremism."

Police identified the suspect as Khalid Masood, 52, on Thursday. Authorities said Masood was born in Kent and detectives believe he was most recently living in the West Midlands. He was known by a number of aliases, police said.

Masood was known to security services as "a peripheral figure" and "was not part of the current intelligence picture," Prime Minister Theresa May told the House of Commons on Thursday.

Police also said Masood was not the subject of any current investigations and there were no prior intelligence reports indicating his intent to carry out the terror attack.

Lawmakers observed a minute's silence in tribute to slain police Constable Keith Palmer, 48, who died despite efforts to revive him by doctors and a passing government minister.

One of the wounded was a tourist who plunged from the bridge into the River Thames. The woman, who was in the city to celebrate her boyfriend's birthday, suffered serious head injuries and has badly damaged lungs, Romanian diplomat Dan Mihalache told Realitatea TV, according to The Associated Press.

She said he had been investigated "some years ago" by the MI5 domestic intelligence service "in relation to concerns about violent extremism."

May added: "He was a peripheral figure. The case is historic. He was not part of the current intelligence picture. There was no prior intelligence of his intent or of the plot."

The prime minster told lawmakers that "the working assumption is that the attacker was inspired by Islamist ideology."

May also paid tribute to government minister Tobias Ellwood, who tried to save the dying police officer. "Yesterday we saw the worst of humanity but we will remember the best," she said.

Mayor Sadiq Khan invited Londoners to an evening vigil and promised "business as usual" in the capital

"London is a city that's been resilient in the face of terror attacks in the past," he told NBC News. "People are returning to work today … we're not going to allow a terrorist to divide our communities or change our way of life."

More police officers than usual were on patrol as the Metropolitan Police aimed to provide "reassurance."

Westminster Bridge remained cordoned off and the surrounding streets — normally thronged with commuters — were eerily quiet except for the buzz of a police helicopter.

Defense Minister Michael Fallon described Wednesday's atrocity as a "lone-wolf attack" but said investigators were still checking "whether other people were involved."

He added: "London is getting back to work. London has seen this before and is taking it on the chin.