Thousands of anti-lockdown demonstrators turned up at Trafalgar Square in London on Saturday for a so-called "We Do Not Consent" rally to protest against restrictions imposed to check the spread of coronavirus, including the current "rule of six" which limits gatherings to a maximum of six people.
The Metropolitan Police issued a statement to warn that it would be stepping up patrols in line with the planned demonstrations, even as it reminded the public that such gatherings could be in breach of regulations designed to protect people from the virus.
It is illegal for people to gather in groups of more than six, unless they are exempt. While protest is one of those exemptions, organisers must submit a risk assessment and must comply with social distancing.
"Officers will, of course, continue to use the approach of engaging, explaining and encouraging people to follow the regulations. However, if people fail to comply, and continue to put themselves at risk, officers will take enforcement action," said Commander Ade Adelekan, who is leading the Met Police operation on Saturday.
"I know there is great frustration to these regulations, but they have been designed to keep everyone safe from what is a lethal virus. By flagrantly gathering in large numbers and ignoring social distancing, you are putting your health and the health of your loved ones at risk," he said.
The police force said its officers will take enforcement action if crowds fail to comply with officers and risk the health of each other and indeed police officers.
"The Met will also not tolerate the level of violence and hostility that has recently been shown to police officers and other members of the public," it said in a statement.
A number of highly trained public order officers as well as mounted officers will be among the highly visible police presence throughout central London, in order to respond "swiftly" to breaches of the coronavirus regulations and scenes of violence, it noted.
Meanwhile, protesters could be seen holding placards reading: "When tyranny becomes law, resistance becomes duty", "Unmask the Truth" and "No More Lies, No More Masks, No More Lockdown", while chants of "take off the mask" echoed loud.
Last weekend, a similar anti-lockdown protest turned violent, resulting in 32 arrests.
"Last weekend it was highly disappointing to see that a small minority of demonstrators targeted officers with violence. Some 15 officers were injured during this protest, with more than 32 arrests being made during the course of the day. I will not tolerate a repeat of this behaviour this weekend and officers will respond quickly to any scenes of violence," added Commander Adekelan.
Saturday's rally comes as London Mayor Sadiq Khan called for tougher curbs for the UK capital, which is now on the government's Covid-19 watchlist.
All its boroughs are now part of 92 areas of concern around the UK, where the death count from the deadly virus is edging towards 42,000 with infection rates continuing on an upward trajectory.
Large parts of Britain are already under strict localised lockdowns, with more than a quarter of the population facing curbs as further rules come in force this weekend.