The capital was swarmed by thousands of demonstrators as a number of protests took place simultaneously.
Many were protesting the Government’s proposed Police, Crime, Sentencing and Courts Bill.
If passed, the legislation would give police in England and Wales more powers to impose conditions on non-violent protests – including those deemed too noisy or a nuisance, with those convicted liable to fines or jail terms.
“Kill the Bill” demonstrators were joined by Extinction Rebellion, and anti-lockdown protesters.
While the majority of attendees arrived and left peacefully, a small minority stayed leading to clashes with police.
The Metropolitan Police said that 107 arrests were made - for offences including breach of the peace, violent disorder, assault on police and breaches of Covid legislation, while one woman was arrested on suspicion of possession of an offensive weapon.
The police said arrests were made after “a small minority” of protesters, who were not social distancing, remained in Parliament Square despite the rest of the demonstrators leaving.
Scotland Yard later added that 10 officers were injured on Saturday, though none of these injuries are believed to be serious.
Commander Ade Adelekan, who led the policing operation for yesterday’s protests, said: “While our advice to people remains not to attend large gatherings, the vast majority of people who attended central London yesterday adhered to social distancing, and engaged and listened to my officers.
“However, as the afternoon wore on it became clear that a small number of people were intent on remaining to cause disruption to law-abiding Londoners.
“Despite repeated instructions from officers to leave, they did not and, amid increasing levels of disorder, arrests were made.
“We should not allow the behaviour of a few individuals who attend these events with the purpose of committing criminal acts to taint the good behaviour of the majority who attended yesterday.”
Protests took place across the UK on Saturday.
Police said they dealt mainly with “peaceful” Kill the Bill protests in London, Newcastle, Birmingham, Liverpool and Dorset.
However, seven people were arrested in Bristol after more than 1,500 people attended a protest, Avon and Somerset Police said.
The M32 motorway was temporarily closed to inbound traffic at junction 3 when a smaller group of protesters occupied the road.
At around midnight, a section 35 dispersal order was issued for the city centre following “several instances of minor disorder between protesters”, police said.
Superintendent Mark Runacres said: “At around midnight there were several altercations between the small number of people who remained in the city centre. We never tolerate violence and so we made the decision to move people on.
“It’s disappointing that once again there were those who refused to listen to our requests to leave and that we had to make arrests.”
There was a low-key response from Northumbria Police as hundreds of people gathered beneath Grey’s Monument in Newcastle.
Protesters, including one who held up a placard saying “we will not be silenced”, cheered as a singer with a guitar performed in opposition to the proposed Bill.
Many took the knee at the Civic Centre and held a minute’s silence for victims of oppression, after which a round of applause broke out.
Dorset Police thanked those who took part in “peaceful protests” in Bournemouth and Weymouth and stuck to the Covid-19 restrictions.
