Video: Chaotic scenes as man runs into double decker bus behind BBC reporter who was live on air

A pedestrian was hit by a double decker bus in London during a reporter's live cross outside the High Court where the parents of 11-month-old Charlie Gard had presented fresh evidence that their terminally ill son should receive experimental treatment.

Bystanders, including the BBC journalist Keith Doyle, were left shocked as a man who appears to have been being chased, runs behind the reporter and collides with the bus and falls onto the busy street.

Mr Doyle slightly turns his head to see what people were shouting about behind him before the man falls out of shot. 

The bus can be heard braking suddenly while people gasp in shock. 

"There's a lot of drama here outside the courts, not quite sure what was going on there but there's a lot of groups, lots of supporters, lot of media attention," Mr Doyle says, continuing his live cross while occasionally looking across his shoulder.

After the incident, Mr Doyle tweeted that the man was ok, with "some scrapes."