Two more victims have been named:
75-year-old Leslie Rhodes died in hospital after his life support was switched off. He was from Streatham, south London.
American tourist Kurt Cochran, 54, was on a dream holiday to London with his wife to celebrate their 25th wedding anniversary. His wife remains in a critical condition in hospital.
This is the last known photo of PC Keith Palmer. It shows a tourist from Florida posing with the policeman outside parliament at around 2pm on Wednesday, just before the terror attack in which he was stabbed to death:
Fifty people were injured in the attack, with 31 receiving hospital treatment. Two are in a critical condition; one has life-threatening injuries.
Updating reporters outside New Scotland Yard, Met Police Assistant Deputy Commissioner Mark Rowley said two police officers remain in hospital with "very significant" injuries.
The terrorist has been named as 52-year-old Khalid Masood, a Muslim convert who was born Adrian Russell Ajao. He is known to have stayed in a hotel in Brighton the night before the attacks where he tried to hire the room for a cheaper price.
Home Secretary Amber Rudd and London Mayor Sadiq Khan joined hundreds of people at a
candlelit vigil in Trafalgar Square on Thursday evening to remember the people who lost their lives.
In total, 10 people have been arrested. Nine people are being questioned by police.
The latest arrests took place in the West Midlands and the North West.
Three women and five men were held in London and Birmingham on Thursday on suspicion of preparation of terrorist acts but Mr Rowley said one person has now been bailed.
Police said searches at five addresses were ongoing and 16 have finished. Detectives have seized 2,700 items, including "massive amounts of computer data"
London attack: Police appeal for information on Khalid Masood - BBC News
This is the moment Theresa May was rushed out of parliament and put into a car by her security team during the terror attack:
