Anti-lockdown protesters and police have clashed at a demonstration in central London as officers tried to shut the event down.
Thousands of people massed in Trafalgar Square on Saturday carrying a variety of signs, flags and placards to take part in a “we do not consent” rally, none appearing to wear face coverings or to social distance.
But the Metropolitan Police said on Twitter that it was asking the crowds to disperse because they were not complying with social distancing rules.
The force said demonstrators will be asked to leave and warned that anyone who stays could be subject to enforcement action.
Officers penned the crowd in Trafalgar Square and water was thrown at them by demonstrators while crowds also chanted “pick your side” at the officers.
Bottles were thrown and police used batons against protesters, leaving some with visible injuries.
At least three protesters and one officer were treated by medical staff.
Police removed sound equipment from Trafalgar Square and several protesters were led away in handcuffs.
Another demonstrator was physically carried away from the scene by officers.
The force said: “Crowds in Trafalgar Square have not complied with the conditions of their risk assessment and are putting people in danger of transmitting the virus.
“This has voided their risk assessment and we have informed the event organisers they are no longer exempt from the regulations.
“We are now asking those in Trafalgar Square to leave. Officers will be engaging with crowds and informing them of this development.
“By leaving now, you can keep yourself safe and avoid any enforcement action being taken by officers.”
Earlier, police searched a man and confiscated a makeshift riot shield he was carrying.
The protest comes a week after a separate event which saw more than a dozen officers injured when a “small minority” targeted police and more than 32 arrests were made.
The Met said it had been engaging with organisers throughout the week to remind them of their legal obligations and explaining the events could be in breach of coronavirus regulations.
While protests are exempt from the “rule of six” in England, organisers must submit a risk assessment and comply with social distancing.
Police said some organisers had done so but where this had not happened the Met will “increase their engagement and encourage attendees to disperse”.
They added that enforcement “remains a last resort but will be undertaken if required”.