This was the shocking moment a runaway police horse collided with a person during the Black Lives Matter march in London today (June 6).

Footage shows protesters running from a police charge as a lone police horse gallops down Whitehall and knocks down a bystander, whose condition is not yet known.

The runaway horse was a result of a mounted police officer losing control of their horse and slamming into a traffic light.

The Metropolitan Police Tweeted: "The officer is currently in hospital, receiving treatment for her injuries which are not life threatening.

"The officer fell from her horse, and we are examining the full circumstances of what took place."

"The horse, uninjured, made its own way back to the stables, nearby." They later said.

The footage has quickly gone viral on Twitter garnering over 500,000 views.

Martin Bobb-Semple who filmed the incident told Newsflare: "I was pretty shocked, to be honest.

"I’ve worked with horses before and I know how aggressive they can get if they’re scared."

Horse runs down Whitehall outside Downing Street and knocks someone over.