The UK police have named 52-year-old Briton Khalid Masood as the man behind the London terror attack yesterday.

The police said that the man had criminal convictions.

Earlier, Islamic State group said through its Aamaq news agency that the London attacker was a 'soldier of the Islamic State

British Prime Minister Theresa May said that the man was once investigated for extremist links but was considered a peripheral figure. She didn't disclose his name. May says police believe the man acted alone and there is no reason to believe "imminent further attacks" are planned.

May has delivered a defiant message after a deadly attack, saying "we are not afraid."

May has told lawmakers in the House of Commons that "yesterday an act of terrorism tried to silence our democracy, but today we meet as normal."

She called the car and knife rampage that killed three victims "an attack on free people everywhere."

Britain's prime minister says people from 11 countries were hospitalized after the attack outside Parliament.

Theresa May said that 12 Britons, 3 French, 2 Romanians, 4 South Koreans, 1 German, 1 Pole, 1 Irish, 1 Chinese, 1 Italian, 1 American and two Greeks required hospital treatment. Police earlier said that seven of the 29 who are hospitalized are in critical condition.

A knife-wielding attacker driving an SUV mowed down pedestrians, killing two on Westminster Bridge before breaching Parliament's grounds and fatally stabbing a police officer. The attacker was then shot dead by police.

France's foreign minister says three French teenagers hospitalized after the attack outside London's Parliament are not in life-threatening condition.

Foreign Minister Jean-Marc Ayrault, after visiting the victims in London, said democratic nations should not be cowed by this kind of attack.

"We must say no to those who want to kill our democracy," he told reporters. "We will not put up walls."

While no information has been released bout the attackers' identity, Ayrault said authorities should fight against the radicalization of young people and against the Islamic State group in particular. Ayrault was at a meeting in Washington about fighting IS when the London attack hit.

The three French teens, part of a large group on a high school trip to London, were among those injured Wednesday.

London's mayor has paid tribute to a slain police officer who tried to stop a knife-wielding attacker who had entered Parliament's grounds.

Mayor Sadiq Khan says that 48-year-old police officer Keith Palmer "was doing the job he loved and protecting our city, protecting Parliament, protecting Londoners, unarmed, and he died in the course of his duty. And I pay tribute to him."

The attacker, who had earlier mowed down pedestrians on Westminster Bridge, was shot dead by police after stabbing Palmer. Two other people were killed in the attack.

Khan says that there have been "13 occasions over the last three or four years where attempts to terrorize us, to kill and to maim, have been thwarted."

Britain's defense secretary has praised the work of police officers after the attack outside Parliament by a knife-wielding man driving an SUV.

Michael Fallon says that a "very urgent investigation" had been going on around the clock to determine whether "anybody else was involved."

Earlier, police said they believe the attacker who killed three people, including a police officer, acted alone and was "inspired by international terrorism."

Police have conducted major raids overnight and detained seven people.

The Spanish Foreign Ministry says that a British national whose mother is Spanish has been identified as one of the people killed in the London attack.

A spokesman says that Spanish consular officials have made contact with Aysha Frade's relatives in Spain's northwestern region of Galicia when her identity was confirmed. He was unable to give any further details.

The regional Voz de Galicia newspaper said that Frade was 43 years old and was teaching Spanish in London.

The official spoke on condition of anonymity in keeping with ministry regulations.

The British Parliament has observed a minute of silence to remember those killed in the attack at that heart of the government.

The sitting Thursday is an important act of defiance, showing a commitment to the values at the core of the nation's government.

A man driving an SUV plowed into pedestrians on Westminster Bridge on Wednesday before he fatally stabbed a police officer on Parliament's grounds. Two other people were killed, and police shot dead the attacker.

Parliament was put into lockdown after the attack.

Earlier

Prime Minister Theresa May condemned the 'sick and depraved terrorist attack' in London yesterday.

A knife-wielding man had gone on a deadly rampage at the heart of Britain's seat of power Wednesday, mowing down pedestrians on London's Westminster Bridge before stabbing an armed police officer to death inside the gates of Parliament. Five people were killed, including the attacker, and about 40 others were injured.

Lawmakers, lords, staff and visitors were locked down after the man was shot by police within the perimeter of Parliament, just yards (meters) from entrances to the building itself and in the shadow of the iconic Big Ben clock tower. He died, as did three pedestrians on the bridge, and the police officer.

British armed police have carried out a raid on a property in the central city of Birmingham.

Police refused to say if the raid was linked to the rampage in the heart of Britain's seat of power. But British media including the Press Association on Thursday quoted an unnamed witness saying that the operation was linked to the attack.

The witness said that police raided an apartment and arrested three men. Police in the West Midlands, where Birmingham is located, directed inquiries about the operation to London's Metropolitan Police.

China says one of its citizens was among 40 people injured in the attack outside Britain's Parliament, and is urging Chinese nationals in the country to avoid crowded areas or traveling alone at night. At the same time, South Korea's acting head of state has instructed the country's Foreign Ministry to help the five South Korean nationals injured in London.