Armed Police have opened fire and shot a person outside the Houses of Parliament.
Several shots were fired at around 2.35pm moments after a loud bang was heard inside the Palace estate.
Three bodies were visible on the floor and the Palace was placed on an immediate lock down.
The House of Commons was suspended by Deputy Speaker Lindsay Hoyle. MPs have been ordered to wait inside the Commons chamber.
People outside the palace could be seen running from the scene when the shots were heard.
A man with a knife was seen within the confines of the palace.
An eye witness said that a car was seen to mow down five people on Westminster Bridge.
Police are then believed to have shot a man who tried to enter the Parliamentary Estate.
The Air Ambulance landed in to Parliament Square.
Twelve police cars and vans were outside the Palace in the moments after the incident.
The dramatic incident comes weeks after it was revealed that UK security services have foiled 13 potential attacks in less than four years, while counter-terrorism units are running more than 500 investigations at any time.
The official threat level for international terrorism has stood at severe, meaning an attack is ‘highly likely’, for more than two years.
Liberal Democrat transport spokeswoman Baroness Randerson said countries seem to have been ‘singled out based on religious beliefs’.
‘Of course safety is paramount at all times and we all need to remain vigilant but this ban needs to be explained in detail,’ she said.