Three men have been arrested after a 24-year-old man was stabbed to death in central London’s Knightsbridge in what police believe could have been a targeted attack.

They marched to Parliament Square in Westminster, brandishing regiment flags and Union flags, and were flanked by a motorbike procession.

The director-general of the BBC, Tim Davie, said it was an ‘option open to those on the ground’ to cut the livestream.