The Westminster terror attack has claimed its fourth victim, a 75-year-old man, police have said.
The man had been receiving hospital treatment after Khalid Masood ploughed through pedestrians on Westminster Bridge and tried to storm Parliament on Wednesday afternoon.
Detectives confirmed the death on Thursday night after the man's life support was stopped.
The Metropolitan Police said: "Next of kin have been informed and are receiving support from specially trained family liaison officers."
The attack, at about 2.40pm on Wednesday, injured some 40 people, some seriously, including police officers.
Earlier on Thursday the third victim was named as American Kurt Cochran.
Mr Cochran, 54, was visiting London with his wife Melissa to celebrate their 25th wedding anniversary.
His wife was injured in the attack and she is in hospital with a broken leg, rib and a cut to the head.
A Facebook post by the couple's family described the loss of Mr Cochran as "heart wrenching".
Aysha Frade, who worked as a sixth form Spanish teacher at the nearby DLD College London, also died in the attack.
A British national, whose mother was Spanish and father was Cypriot, she lived in London with her two young daughters and her husband.
She was walking to meet her daughters from school when the attack happened.
PC Keith Palmer, a Parliamentary and diplomatic protection officer, was fatally stabbed by Masood before the attacker was shot dead by armed police.
His family paid tribute to "a wonderful dad and husband" as the Metropolitan Police said it would not re-issue his shoulder number.
In a statement, PC Palmer's family said: "Keith will be remembered as a wonderful dad and husband. A loving son, brother and uncle. A long-time supporter of Charlton FC.
"Dedicated to his job and proud to be a police officer, brave and courageous. A friend to everyone who knew him. He will be deeply missed. We love him so much.
"His friends and family are shocked and devastated by his loss."