LONDON (Reuters) - A man with a St George’s English flag was pinned to the ground by police outside the Downing Street residence of Prime Minister Boris Johnson on Thursday, a Reuters photographer at the scene said.

A spokeswoman for Johnson’s office said she was unaware of any protest and declined to comment further. There was no immediate information from police.

On the day the United Kingdom had been due to leave the European Union, a few hundred pro-Brexit campaigners sought to approach the gates of Downing Street where police stopped them. A few protesters were detained.