LONDON (AP) — A protester was arrested Wednesday after hurling eggs and vitriol at King Charles III and Camilla, the queen consort, as they walked in the northern England city of York.

The incident happened as the king and his wife were entering York through Micklegate Bar, a medieval gateway where monarchs are traditionally welcomed to the city.

Video footage showed several eggs in motion and smashed on the ground. None appeared to hit the royal couple, who continued to greet crowds.

Several police officers could be seen grappling with a man at a crowd barrier. Britain’s PA news agency reported that he booed and shouted “This country was built on the blood of slaves” as he was being detained.

Other members of the crowd tried to drown him out by chanting “Shame on you” and “God save the King.”

Charles and Camilla traveled to York as part of a series of engagements around the U.K. marking the start of the new king’s reign. They also visited the city’s cathedral, York Minster, and unveiled a statue of the king’s mother. Queen Elizabeth II, who died in September after 70 years on the throne.