A 13-year-old girl has been arrested on suspicion of assaulting a police officer at a pro-Brexit protest in London.

The teenager was among four people detained at the demonstration - where activists wore yellow hi-vis jackets, similar to those worn in recent weeks by anti-government protesters in France.

On Westminster Bridge on Saturday, people were seen burning an EU flag and some protesters chanted: "We want Brexit. When do we want it? Now."

Used smoke bombs were also seen discarded on nearby streets.

Scotland Yard said: "Four arrests have been made following protests on Westminster Bridge, SW1 at approximately 11am today.


"Three men arrested on suspicion of public order offences. A 13-year-old girl was also arrested on suspicion of assault on police."

The teenage girl was later released under investigation on Saturday night.