3 dead as attacker goes on rampage near UK parliament

At least three people died and 20 were injured when an attacker rammed a car into crowds of people before stabbing a police officer in the grounds of the UK Parliament. One woman was pulled alive from the River Thames amid chaos in the area, the heart of political life in Britain. The assailant also died, police said, as they announced a "full counter-terrorism investigation". Parliament was placed on lockdown and lawmakers were forced to remain in the main debating chamber of the House of Commons as firearms officers rushed to the scene outside.

The Mayor of London, Sadiq Khan, said the incident -- on the one-year anniversary of the Brussels attacks -- was "being treated as a terrorist attack until the police know otherwise." One of those who died was a police officer. Pictures showed scenes of carnage in the aftermath of the attack, which happened as parliament was in session.