LONDON -- Security is tightening in London ahead of the coronation of King Charles III in what will be the city’s largest one-day mobilization of Metropolitan Police officers seen in decades, the force said on Wednesday.

There will be more than 11,500 officers on duty on coronation day, with over 29,000 deployments in the lead-up to the day and over the rest of the bank holiday weekend, the force said in a statement updating the breadth and scale of Operation Golden Orb, which has been in the works for months.

The multi-layered security operation will see police lining the processional route, managing crowds and road closures, protecting “high-profile individuals,” and carrying out searches with specialist teams, the force said, while authorities will also utilize facial recognition technology in central London.

“The watch list will be focused on those whose attendance on Coronation Day would raise public protection concerns, including those wanted for offences or have an outstanding warrant for arrest issued by the courts, or those under relevant offender management programmes in order to keep the public safe,” the statement says.

Officers from the dogs unit, firearms unit, marine support, and Special Constabulary will also be standing by, ready to respond. Metropolitan Police are also working closely with their partners and colleagues from other forces, and also at British Transport Police, City of London Police and Thames Valley Police.

“Our tolerance for any disruption, whether through protest or otherwise, will be low. We will deal robustly with anyone intent on undermining this celebration,” the force’s statement said.

On Tuesday night, police arrested a man and blew up a suspicious bag outside Buckingham Palace after he threw a number of items – believed to be shotgun cartridges – into the palace grounds.

The incident happened four days before the coronation, during which King Charles and his wife, Queen Consort Camilla, will be crowned at London’s Westminster Abbey. It’s an event that is expected to attract hundreds of thousands of people to London’s city streets, including tourists from out of town. Foreign dignitaries, heads of state and members of the Royal Family are also expected to attend the prominent event.

‘AN EXTREMELY IMPORTANT MOMENT’

The coronation involves "one of the most important security operations that the country has put into plan,” Security Minister Tom Tugendhat told Times Radio.

"This is an enormously important moment for the country," Tugendhat said.

"The police are, to put it mildly, all over it, and our intelligence and other security forces are extremely aware of the challenges that we face and ready to deal with them -- as the police did quite brilliantly yesterday."

Buckingham Palace preparing for coronation

Police said a 59-year-old man was arrested in Tuesday night’s incident. Chief Superintendent Joseph McDonald said: “Officers worked immediately to detain the man and he has been taken into police custody.

“There were no reports of any shots fired, or any injuries to officers or members of the public. Enquiries are ongoing.”

‘DIDN’T SEE THIS WHEN THE QUEEN DIED’

On Wednesday morning, security teams and police officers were out in full force while roads were blocked off around Buckingham Palace as tourists and international media began to descend on the city for the historic event.

“Security is tight. It’s very, very tight and it has been for a while,” royal commentator Afua Hagan told CTVNews.ca.

“The road closures are incredible … So many more police on the streets, they are really making their presence felt, patrolling on horseback. There just appears to be more of a presence … We definitely didn’t see this when the queen died, not from any of the royal weddings.”

With so many world leaders in attendance, royal commentator Richard Berthelsen said there will be added emphasis from police forces on making sure security concerns are addressed.

“It’s a very delicate thing,” he told CTVNews.ca. “But the British are very experienced. They had a much larger group of heads of state in September [for Queen Elizabeth II’s funeral].”

London Metropolitan Police’s Deputy Assistant Commissioner Ade Adelekan has said there is no intelligence of any known threats, Reuters reported.

That said, police are expected to grapple with protesters taking advantage of the world’s eyes on the coronation to draw attention to their own causes. However, new laws passed this week provide authorities with increased powers to deal with protesters.

The U.K. government has fast-tracked new laws in what feels “rushed through,” in time for the coronation, Hagan said. The new laws include prison sentences for protesters who block roads or anyone who locks on to other people, objects or buildings.

Security on The Mall in London

Under the new policing powers, given royal assent by Charles on Tuesday, protesters will also be subject to stops and searches by police if they are suspected to be setting out to cause disruption.

“They’re basically saying, ‘We’re going to come down hard on you,’” Hagan said.

“I think there is a rise of republican feeling and the government is afraid of what could happen,” Hagan added, referring to demonstrations that are being planned for coronation day by anti-monarchy groups.

While police have said protestors are free to hold peaceful demonstrations, "what we will not stand for and what we will not have is anyone committing criminal acts in the name of protest," Adelekan said.

"We will come down very swiftly to intervene, to make sure that people that are going about their normal business that just want to enjoy the coronation are not interfered with."

Despite letters from the Home Office to protesters warning them of the new policing powers, the anti-monarchy group Republic, which will be protesting under the banner “Not My King,” said it still planned to stage protests.

While the anti-monarchy groups are preparing to protest in Trafalgar Square and along the procession route, at the other end of the spectrum, royal watchers who are keen to celebrate King Charles’ coronation are also getting ready in anticipation.

Some of them have already begun to camp out with folding chairs, tarps and tents on The Mall, the iconic road leading up to Buckingham Palace that has been blocked off to traffic and members of the public, as they stake a claim to prime viewing locations ahead of the carriage procession on Saturday.

Royal watchers camping before coronation

In an attempt to help ease congestion and guide traffic, the U.K. government has put out a guide for people planning to attend the coronation on how to safely get around London.

The guide notes that the areas in and around Hyde Park, Buckingham Palace, Westminster Abbey, Whitehall, St James’s Park, The Green Park and Trafalgar Square are expected to be very crowded while the National Rail and London Underground stations in surrounding areas will be quite busy.

The guide also notes that there may be temporary safety measures implemented at transport stations such as lineups, closures or trains not stopping at certain stations.

On May 2, the government of Canada also updated its travel advice for those visiting the United Kingdom to attend the coronation. With large crowds expected in London leading up to and including coronation day on May 6, travellers are being warned of disruptions to traffic and public transportation.

Canadians are advised to plan their trip carefully and expect delays while following the advice of the local government. The travel advisory also urges Canadian visitors to exercise a “high degree of caution” due to the threat of terrorism in Europe. The notice points to attacks that have been carried out in several European cities, including those in the United Kingdom. These attacks include random violent incidents in public areas, such as knife and vehicle attacks as well as explosions.

The streets are also expected to be busier over the bank holiday weekend as drinking establishments in England and Wales have received permission to stay open later to allow people to “enjoy an extra pint or two,” Home Secretary Suella Braverman said in March.

Instead of closing at 11 p.m. local time, pubs, clubs and bars will stay open for an extra two hours between May 5 and May 7, which means they will close at 1 a.m.

With files from Reuters