Everything you need to know
Police have confirmed that eight arrests have been made during raids after the Westminster attack.
Acting Deputy Commissioner and Head of Counter Terrorism Mark Rowley spoke of how hundreds of detectives have worked through the night, searches were made at six addresses.
A total of four people were killed, this was a woman in her 40s, a man in his 50s, PC Keith Palmer and the attacker.
Seven of the injured are still in hospital in critical condition.
Rowley stated that a further 29 had been treated at hospital.
The attack took place on Wednesday afternoon when a man drove a car into pedestrians on Westminster Bridge.
After this he then stabbed a policeman and was shot down by police.
Rowley, said in a statement outside Scotland Yard: “The inquiries in Birmingham, London and other parts of the country are continuing.”
“It is still our belief – which continues to be borne out by our investigation – that this attacker acted alone and was inspired by international terrorism.”
“To be explicit, at this stage we have no specific information about further threats to the public.”