More than 30 people have been arrested after violent scuffles between protesters and police at a large anti-vax, anti-lockdown protest in central London.

Hundreds descended on Trafalgar Square on Saturday afternoon for a “Resist And Act For Freedom” rally, including some bearing 5G conspiracy placards and signs declaring Covid-19 a “hoax”, with police repelled by human blockades as they tried to clear the area.

Dozens of officers, including some on horseback and in riot gear, were pushed back by crowds who chanted and cheered, with some throwing missiles.

At least one protester was seen with a bloodied head while another was seen receiving medical attention on the ground, but the London Ambulance Service did not immediately have information on any injuries.

The London landmark was cleared of protesters after 5pm, and Scotland Yard said 32 people were arrested.

The force said the large crowds were “putting themselves and others at risk” just a day after Mayor of London Sadiq Khan warned it is “increasingly likely” restrictions will be needed to slow the spread of coronavirus in the capital, adding he was “extremely concerned” about the rate of transmission in London.

The number of cases per 100,000 people over seven days is reported to have increased in London from 18.8 to around 25.

Police said they had to take “enforcement action to disperse” the crowds after officers who had attempted to “explain, engage and encourage them to leave” were met with “hostility” and “violence” from some demonstrators.

Traffic around Trafalgar Square came to a halt during the demonstration, with one protester seen apparently spitting through the open window of a taxi whose driver had beeped the horn in frustration.

The protest was advertised with an image showing a vaccine bottle and urging people to “Come together, resist and act”.

Protests are exempt from new legal restrictions introduced on Monday limiting groups to six, but only if it is “organised in compliance with Covid-19 Secure guidance”, the Government said.

One speaker at the rally, Professor Dolores Cahill of University College Dublin (UCD), expressed the view that the coronavirus vaccine will “make people sick”, going against mainstream scientific opinion.

The UCD has previously disassociated itself from views on Covid-19 aired by Prof Cahill, who also chairs the Eurosceptic Irish Freedom Party, the Irish Times reported.

Vaccines are the most effective way to prevent infectious disease and have virtually eradicated smallpox, polio and tetanus in the UK, the NHS says.

But if people stop getting vaccinated then diseases can quickly spread again, it said, pointing to a spike in measles and mumps between 2016 and 2018.

There is no evidence that vaccines cause autism, allergies or other conditions, weaken the immune system in any way, or contain harmful ingredients, it adds.

The World Health Organisation says immunisation prevents two to three million deaths per year.