The British authorities tried to reassure about security after the arrest of a suspected gunman near Buckingham Palace, confirming that they will deploy more than ten thousand police during the coronation ceremony of King Charles III and his wife Camilla on Saturday.

Seventy years after the coronation of Queen Elizabeth II, Britain is preparing to crown its new king. In a sign that the countdown has begun, some of the royal family's staunchest supporters have begun to take up positions on the long avenue from Buckingham Palace.

Tens of thousands of Britons and tourists are expected to line the route that Charles and Camilla's motorcade will take between Buckingham Palace and Westminster Abbey. About 2,300 people were invited to the ceremony, including 100 heads of state.

Eight months after Operation London Bridge, the codename for organizing Elizabeth II's funeral, British police are carrying out Operation Golden Orb for the king's coronation.

Secretary of State for Security Tom Tugendhat said Wednesday that the ceremony, which culminates in three days of festivities, will be "one of the most important security operations" Britain has witnessed.

He added that "our intelligence services and other security forces are fully aware of the challenges we face and are ready to meet them, as the police did brilliantly" on Tuesday evening.

On Tuesday evening, around 19:00 (18:00 GMT), a man suspected of being armed was arrested after he approached the Buckingham Palace fence and threw objects believed to be firearm cartridges into the palace garden.

A police statement said, "A security cordon was set after a suspicious bag was found in the man's possession," noting that experts detonated it as a precaution. Police said the suspect had been arrested and later said they were not currently treating the case as terrorism-related.

King Charles was not in the palace at the time, but he had received, shortly before that, Australian Prime Minister Anthony Albanese, as part of one of the diplomatic meetings preceding the coronation.

On Saturday, more than 11,500 members of the security forces will be deployed, as announced by the London police. "This will be the biggest one-day mobilization of police in decades," said Adi Adelekan, a Scotland Yard official.

Over a week, 29,000 security personnel will be deployed.

In central London, the police will use facial recognition technology. Snipers will be posted on the rooftops.

In addition to the threat of terrorism, the police closely monitor climate activists, many of whom have come to London in recent days, as well as anti-monarchists.

The Republic group had planned a rally in Trafalgar Square and along the King's motorcade for Friday morning. Organizers said they expect more than 1,000 people to participate.

And London's police warned, saying, "Our tolerance for disturbances, demonstrations or any other matter will be weak," adding, "We will deal firmly with anyone who intends to disrupt this celebration."

Seven thousand soldiers will take part in the procession, which will run between Buckingham and Westminster. Edward William FitzAlan-Howard, who is in charge of organizing the coronation, said it would be "an event of great pomp".

The religious ceremony -- the King being the head of the Anglican Church -- will last two hours. "It's a good time to remember the pride we feel in our great country and our unwritten, thousand-year-old constitution," he added.

Upon their return to Buckingham, Charles and Camilla will greet the audience from the balcony. And if Prince Harry, who left the country amid turmoil in 2020, will attend the ceremony in Westminster, he will not appear with the family on the balcony, according to British media.

A six-minute air show will be held over London.

In addition to the coronation ceremony, Britain is preparing for three days of festivities. The people were invited to participate Sunday in a "big lunch" as part of the parties taking place in the neighborhoods, where the "coronation tart" will be on the menu, the recipe of which was revealed by the palace in mid-April.

And at night, a concert will be held at Windsor Castle in west London, which will be attended by 10,000 randomly selected Britons. Katy Perry, Lionel Richie and tenor Andrea Bocelli lead a special poster for this concert marked by the absence of British stars.

Finally, the royal family will invite Britons to do volunteer work on Monday, May 8, which will be a day off.