Londoners are in mourning after five people were killed and 40 injured in an attack outside the British parliament on Wednesday when a man mowed down pedestrians, then stabbed a police officer before being shot dead.
The car struck pedestrians on Westminster Bridge - a spot popular with tourists because of its views of Big Ben and the Houses of Parliament - before crashing into the railings outside the heavily guarded parliament building.
The police officer and the attacker are among those killed.
Londoners have started a twitter trend #WeAreNotAfraid, in a show of defiance against the attacker - who police suspect was motivated by Islamist terrorism.