Police say they arrested 107 people after a "Kill the Bill" protest in central London on Saturday.
Those detained were held for a variety of reasons including breach of the peace, violent disorder, assault on police, and breaches of COVID-19 legislation.
One woman was arrested on suspicion of possessing an offensive weapon.
Scotland Yard previously said that 10 officers had been injured, though none are believed to be seriously hurt.
Protesters also gathered in places including Newcastle, Birmingham, Liverpool and Dorset.
They are unhappy about new legislation which would give police in England and Wales more powers to impose conditions on non-violent protests.
That could include demonstrations that are considered too noisy or a nuisance – with those convicted possibly facing fines or jail terms.
Commander Ade Adelekan, who led the Metropolitan Police’s operation, said that while the "vast majority" of those attending Saturday’s protest had social distanced and listened to officers, "a small number were intent on remaining to cause disruption".
He added: "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."
Avon and Somerset Police said more than 1,500 people attended a protest in Bristol, with seven arrests.
At about midnight, a section 35 dispersal order was issued for the city centre following "several instances of minor disorder between protesters", the force said.
Northumbria Police kept their response low-key as hundreds of people gathered beneath Grey’s Monument in Newcastle.
And in Dorset, officers thanked those who took part in "peaceful protests" in Bournemouth and Weymouth while abiding by coronavirus restrictions.