London attack

The assault, which came on the one-year anniversary of the Isis bomb attacks in Brussels, brought carnage to Westminster, the heart of political life in Britain.

Among the dead were a police officer and the assailant, police said, announcing a "full counter-terrorism investigation." A woman was pulled from the River Thames alive, but with serious injuries.

Police and ambulance crews were called at 22:33 BST on Wednesday to reports of a man in possession of a knife and injuring people.

Up to six injured people were found at the scene; one woman was pronounced dead a short time later.

The man was arrested at 22:39; a taser was discharged by one of the arresting officers.

Terrorism is one possible motive being explored, the Metropolitan Police say.