The assailant was killed too in the attack just outside the Parliament.
Acting Deputy Commissioner & national lead for Counter Terrorism Policing Mark Rowley said: “The suspected attacker was shot dead by an armed officer – meaning five people in total have died.”
“At this stage – but it may change – we believe approx 40 people were injured including three police officers,” Rowley said.
Investigation into the matter is currently going on.
British PM Theresa May said in a statement: “We will all move forward together, never giving in to terror, and never allowing the voices of hate and evil to drive us apart.”