Shock in London following a terrorist attack at Westminster.

Four people have died in the attack, including a police officer who was stabbed.

A man was shot dead after he drove his car onto the pavement of Westminster Bridge, and ploughed into pedestrians, before smashing into the railings and stabbing a policeman.

Former Newstalk ZB reporter Josh White told Rachel Smalley the mood was much more downbeat than normal as he commuted home.

"I don't know if it's disbelief, because we've been expecting something like this, but it's just shock. Shock that this has happened in the middle of the city in what is otherwise a normal Wednesday."

LISTEN ABOVE AS JOSH WHITE SPEAKS WITH RACHEL SMALLEY