London police say a 75-year-old man injured in the attack on Westminster Bridge has died of his wounds.

In a statement late Thursday, police said life support was withdrawn from the man and his family has been notified.

The announcement brings to four the number of victims killed in the attack Wednesday in central London. The man identified as the driver of the car that rampaged across the bridge into pedestrians was also killed by police after he jumped out and stabbed a police officer to death.

The man's death increases the death toll from Wednesday's attack to four victims.