Islamic State claimed duty for the assault in a press release issued by its Amaq information company, however didn't identify Masood and gave no particulars. It was not clear whether or not the attacker was immediately related to the jihadist group.
Police stated Masood, 52, was born within the county of Kent in southeast England and was most just lately dwelling within the West Midlands area of central England.
"Masood was not the topic of any present investigations and there was no prior intelligence about his intent to mount a terrorist assault," the Metropolitan Police stated in a press release.
"Nevertheless, he was recognized to police and has a variety of earlier convictions for assaults, together with GBH (grievous bodily hurt), possession of offensive weapons and public order offences."
LIVE UPDATES OF WESTMINSTER ATTACK
Prime Minister Theresa Might earlier informed parliament the attacker had as soon as been investigated by the MI5 intelligence company over considerations about violent extremism, however was a peripheral determine.
Throughout 5 minutes of mayhem within the coronary heart of London on Wednesday, Masood sped throughout Westminster Bridge in a automotive, ploughing into pedestrians. He then ran via the gates of the close by parliament constructing and fatally stabbed an unarmed policeman earlier than being shot lifeless. http://tmsnrt.rs/2napbkD
Police arrested eight individuals at six places in London and Birmingham within the investigation into the assault, which Might stated was impressed by a warped Islamist ideology.
The Enterprise rental automotive firm stated the car used within the assault had been rented from its Spring Hill department in Birmingham, which is situated within the West Midlands."An worker recognized the car after seeing the licence plate in a picture on-line. We ran one other examine to confirm, and instantly contacted the authorities," stated firm spokesman John Davies.
About 40 individuals have been injured within the assault, of whom 29 stay in hospital, seven in important situation.
The assault passed off on the primary anniversary of assaults that killed 32 individuals in Brussels, and resembled Islamic State-inspired assaults in France and Germany the place automobiles have been pushed into crowds.
The lifeless have been two members of the general public, the stabbed policeman and Masood.
"My ideas, prayers and deepest sympathy are with all those that have been affected by yesterday's terrible violence," Queen Elizabeth stated in a message.
U.S. vacationer Kurt Cochran was named as one of many lifeless in a Fb submit by member of the family Shantell Payne.
"With a heavy coronary heart I need to cross the unhappy information of our lovely brother, father, husband, son and pal Kurt Cochran, he couldn't overcome the accidents he acquired within the London terror assaults," Payne wrote.
Her submit stated Cochran's spouse, Melissa Payne Cochran, was in hospital with a damaged leg and rib and a minimize on her head however would recuperate.
U.S. President Donald Trump paid homage to Cochran in a tweet, calling him "an excellent American" and expressing condolences to his household and pals.
Westminster Bridge and an space round parliament have been nonetheless cordoned off early on Thursday and forensic investigators in mild blue overalls examined the scene the place the attacker was shot. The bridge re-opened on Thursday afternoon.
It was the deadliest assault in Britain since 2005, when 52 individuals have been killed by Islamist suicide bombers on London's public transport system. Police had given Wednesday's dying toll as 5 however revised it to 4 on Thursday.
The casualties included 12 Britons, three French youngsters, two Romanians, 4 South Koreans, one German, one Pole, one Chinese language, one American and two Greeks, Might stated.
"A terrorist got here to the place the place individuals of all nationalities and cultures collect to have fun what it means to be free, and he took out his rage indiscriminately towards harmless males, ladies and youngsters," stated Might.
A minute's silence was held in parliament and in entrance of police headquarters at 0933 GMT, in honour of the victims - 933 was the shoulder quantity on the uniform of Keith Palmer, the policeman who was stabbed to dying.
Might was in parliament on the time of the assault, a brief distance away from the spot the place the attacker was shot. She was whisked away because the chaos erupted.
A authorities minister was extensively praised for making an attempt to resuscitate Palmer, strolling away from the scene with blood on his palms and face.
Many have been shocked that the attacker was capable of trigger such mayhem within the coronary heart of the capital outfitted with nothing greater than a employed automotive and a knife.
"This type of assault, this lone-wolf assault, utilizing issues from day by day life, a car, a knife, are rather more troublesome to forestall," Defence Minister Michael Fallon advised the BBC.
Three French high-school college students aged 15 or 16, who have been on a faculty journey to London with fellow college students from Brittany, have been among the many injured.
French Overseas Minister Jean-Marc Ayrault travelled to London to point out solidarity and met a few of the different college students who have been on the varsity journey and their households at a lodge close to the hospital the place the injured have been being handled.
He advised reporters the lives of the three kids weren't in peril. Ayrault later attended the session in parliament the place Might spoke. France has been hit by repeated lethal Islamist assaults over the previous two years.
Might stated the truth that regular life was happening throughout Britain was the best response to the assault.
"It's in these actions – tens of millions of acts of normality – that we discover the most effective response to terrorism, a response that denies our enemies their victory," she stated.