She held a sign saying "f*** imperialism, abolish monarchy". Officers appeared behind her and took her away, prompting the crowd to applaud. One man shouted: "Let her go, it's free speech," while others yelled: "Have some respect."
[...]
During the first proclamation of Charles, the Lord Lyon King of Arms gave a speech before declaring "God save the King", which the crowd repeated.

Two anti-royalist protesters were arrested in the U.K. over the weekend amid King Charles III's ascension to the throne, with one activist calling the moves "an outrageous assault on democracy"
[...]One anti-royalist protester who got arrested on Sunday was close to a remembrance ceremony at Mercat Cross in Edinburgh, by St Giles' Cathedral, where the Queen's coffin will lie on Monday.
[...]
Symon Hill, 45, was also arrested for shouting "who elected him?" during a reading of a proclamation in Oxford, England on Sunday. ...Speaking to The Guardian, Hill said: "I don't think I've ever seen anyone arrested on such threadbare grounds, let alone experienced it myself.
[...]
A Thames Valley police spokesperson said: "A 45-year-old man was arrested in connection with a disturbance that was caused during the county proclamation ceremony of King Charles III in Oxford.

"He has subsequently been de-arrested < wipes tears > and is engaging with us voluntarily as we investigate a public order offense. The man was arrested on suspicion of a public order offense [under section 5 of the Public Order Act 1986]."

I was arrested today in #Oxford after I voiced my opposition to the proclamation of "#CharlesIII". Can we be arrested simply for expressing an opinion in public? I was arrested under the Police Bill passed earlier this year. This is an outrageous assault on democracy.#NotMyKing

— Symon Hill (@SymonHill) September 11, 2022