Four dead, including police officer, 20 injured in UK parliament attack

Scene outside UK parliament where four people were killed in a suspected terror attack. 

At least a dozen people were injured and four reported dead in London on Wednesday after a car crashed into pedestrians near the British parliament and an assailant stabbed a policeman in what police called a terrorist incident.

The knifeman was then shot by police in the shadow of Big Ben, where he had tried to force his way into a courtyard just outside the Houses of Parliament.