Demonstrations against the monarchy take place in London, as well as in Glasgow in Scotland and Cardiff in Wales.
Police have arrested the leader of the anti-monarchy group Republic just hours before the coronation of King Charles III.
Republic said its leader Graham Smith was detained Saturday morning and a photo posted on Twitter showed him on the ground surrounded by police officers.
The group had said it would stage the largest protest against a British monarch in modern history. Protesters wore yellow T-shirts to stand out and held up signs that read ‘Not My King’.
They spent most of the service booing or singing songs, such as “He’s just a normal man”.
However, London police had warned they would take action if protesters attempted to “interfere with the fun and celebration of the day”, and they formed a circle around the group.
“It’s disgusting and hugely exaggerated,” said Kevin John, 57, a Devon salesman who was one of the protesters.
“It is also hugely counterproductive by the police as it has just created a huge amount of publicity for us. It’s totally crazy.”
Police did not confirm Smith’s arrest, but said they had arrested four people on suspicion of causing a public disturbance and three people on suspicion of possessing items to cause criminal damage in what they called a “significant police operation” .
Republic said hundreds of its plates had been seized.
Protests also took place in Glasgow in Scotland and Cardiff in Wales, with placards held up reading: “Abolish the monarchy, feed the people.” On social media, many contrasted the UK’s cost-of-living crisis with the pomp and circumstance on display at the coronation.
‘A true democrat’
Royal biographer Christopher Wilson told Al Jazeera that the king has seen protesters all his life and is used to demonstrations.
“He, I think, is a real Democrat who believes in free speech,” he said.
“The republican movement is not a terrorist movement in any way. It’s just a protest vote and they have a right to free speech. After all, Britain should be the cradle of democracy. Freedom of expression is one of the great principles of our lives,” he added.
Although the protesters were outnumbered compared to the tens of thousands who gathered on the streets of London in support of the king, polls suggest that support for the monarchy is on the wane and is weakest among young people.
With the crown passing from Queen Elizabeth to her less popular son, Republican activists hope Charles will be the last British monarch to be crowned.
While many other European monarchies have come and gone, or shrunk much in size and importance, the British royal family has remained remarkably resilient.
In the UK, polls show that the majority of the population still want the royal family, but there is a long-term trend of declining support.
A YouGov poll last month found that 64 per cent of people in the UK said they have little or no interest in the coronation. Among 18- to 24-year-olds, the number showing little or no interest rose to 75 percent.
More than 11,000 police officers patrol for the coronation, the largest ceremonial event in the British capital for 70 years.