Tributes have been flooding in for the police officer and two members of the public who were killed in a car and knife attack in Westminster.

Using the hashtag #WeAreNotAfraid, thousands of people offered their condolences the member of the Metropolitan Police.

The assailant, dressed in black and armed with two large knives as he rammed into members of the public before crashing his car into the rails outside Parliament.

Scotland Yard said the attacker, who is believed to have acted alone, then repeatedly stabbed a police officer, before being shot dead by the officer's colleagues.

A further 20 people were injured in the attack, some with "catastrophic" injuries.

Labour leader Jeremy Corbyn said: “Our thoughts are with the victims of this horrific attack, their families and friends.

“The police and security staff have taken swift action to ensure the safety of the public, MPs and staff, and we are grateful for them.”

Susan Rice, President Barack Obama’s former national security adviser, said: “We stand in solidarity with our ally as Britons face with characteristic strength continued threat of terrorism. Condolences.”