Death toll rises after terrorist attack in LondonThree women and five men are held by police after overnight raids
The Westminster terror attack has claimed its fourth innocent victim, as police confirmed that a 75-year-old man has died in hospital.
A Scotland Yard spokesman said the man had been receiving medical treatment in hospital following the attack and life support was withdrawn yesterday evening.
"Next of kin have been informed and are receiving support from specially trained family liaison officers," he added.
The attacker who brought terror to the streets of the capital has been named as Khalid Masood and detectives investigating Wednesday's attacks on Westminster Bridge and at the Houses of Parliament said they had arrested three women and five men on suspicion of preparing terrorist acts.
The suspects were held in raids in London and Birmingham as neighbours of Masood, a 52-year-old with a string of criminal convictions including possession of a knife, spoke of their shock.
Three people were killed when the knife-wielding attacker ploughed a car through pedestrians on Westminster Bridge, before storming the Parliamentary estate. He was shot dead.
Unarmed PC Keith Palmer died after being stabbed at the Houses of Parliament.
The Westminster Bridge victims include a US tourist Kurt Cochran, who was celebrating his wedding anniversary, and mother-of-two Aysha Frade, who worked in administration at a sixth-form school.
Scotland Yard said Masood was not the subject of any current investigations before Wednesday's outrage and there was "no prior intelligence about his intent to mount a terrorist attack".
However, he was known to police and MI5 and had convictions for assaults, including GBH, possession of offensive weapons and public order offences.
Masood was born in Kent on Christmas Day in 1964 and detectives believe he was most recently living in the West Midlands. He was also known by a number of aliases.
One former neighbour, Iwona Romek, speaking in Winson Green, Birmingham, said she could not believe her eyes when she realised the man who had lived near her was the man responsible for the attack.
She said: "Now I'm scared that someone like that was living close to me."
In Trafalgar Square, crowds gathered for a candlelit vigil in memory of the victims yesterday evening. They had responded to a personal invitation by London mayor Sadiq Khan to come together in solidarity.
In praise of the bravery of the emergency services responding to the attack, the mayor said: "When Londoners face adversity we always pull together. We stand up for our values and we show the world we are the greatest city in the world."
Among those caught up in events was Belfast-born broadcaster Eamonn Holmes, who revealed how he feared for his wife Ruth Langsford's life after hearing of the attack.
A shaken Eamonn told the Daily Mail that Westminster Bridge is the route she usually takes when driving home after Wednesday's broadcast of Loose Women on ITV.
"Her normal route home would be within three minutes to this bridge and across there and when the news broke later - because it took 10, 15 minutes for the news to come out - I thought "Where's Ruth?"
"And I couldn't get in touch with her!"
By sheer luck, Ruth changed her routine. "It turned out amazingly she went in a different direction, it was just some freaky chance she went in a different direction," he said.
Earlier, Prime Minister Theresa May disclosed the terrorist behind the attack was British-born and was once investigated in relation to concerns about violent extremism some years ago, but was a "peripheral figure".
Masood had spent time in jail, but not for terrorist-related offences.
As police and intelligence agencies mounted a massive investigation to piece together the killer's movements in the lead-up to the attack:
n Searches were carried out at three addresses in Birmingham and one each in east London, Brighton, south-east London and Carmarthenshire.
n A 39-year-old woman was arrested in east London while a 21-year-old woman and a 23-year-old man were held at one address in Birmingham.
n A 26-year-old woman and three men aged 26, 27 and 28 were arrested at another address in Birmingham.
n They were all held overnight while a 58-year-old man was arrested on Thursday at a third address in Birmingham.
n Investigators are working on the basis that the attacker acted alone.
n Car firm Enterprise confirmed the Hyundai used in the attack was one of its vehicles.
The Prime Minister addressed MPs as they gathered at the usual time inside the Palace of Westminster.
In a defiant message to a packed House of Commons, Mrs May said: "We will never waver in the face of terrorism."
Paying tribute to PC Palmer, she said: "He was every inch a hero and his actions will never be forgotten."
The officer's family described him as "brave and courageous", saying his friends and relatives are "shocked and devastated".
Meanwhile, Islamic State made its first public pronouncement since the atrocity, claiming: "The attacker yesterday in front of the British Parliament in London was a soldier of the Islamic State executing the operation in response to calls to target citizens of coalition nations."