Bricks, glass bottles and eggs have been thrown at officers during a third "Kill The Bill" demonstration in Bristol – with the police saying that protesters shone lasers in their faces.
Fireworks were also launched at Avon and Somerset Police’s mounted division, with one force covered in paint.
More than 1,000 people were rallying in the city centre, but tensions rose at 10pm last night as officers wearing helmets and holding shields began calling for the crowd to disperse.
Prime Minister Boris Johnson condemned the violence in a tweet on Saturday morning.
"Last night saw disgraceful attacks against police officers in Bristol," he wrote. "Our officers should not have to face having bricks, bottles and fireworks being thrown at them by a mob intent on violence and causing damage to property. The police and the city have my full support."
Ten arrests have been made – and three of those held had also been detained in connection with the violent disorder seen last Sunday.
Superintendent Mark Runacres said: "The majority of people acted peacefully however there was a minority who showed hostility to officers."
Sky’s correspondent Dan Whitehead, who was in Bristol, reported that the police opted to change tactics five hours into the protest because protesters weren’t going home – and said crowds eventually dispersed.
Matthew Dresch, a journalist with the Daily Mirror, has claimed that he was assaulted by officers during the protest despite declaring that he was from the press.
"I was respectfully observing what was happening and posed no threat to any of the officers," he wrote in a tweet that contained video of the incident.
Police later said they were aware of the video and were making efforts to contact the journalist.
In a statement on Twitter, the force added: "A free press is a cornerstone of our democracy and we fully respect the media’s vital role in reporting events fairly and accurately."
Demonstrators could be heard chanting "Justice for Sarah" and "Who do you protect?", and some of those present were seen dancing to music despite heavy rain.
A large police presence was on duty throughout the night, with horses and dogs used to help move the crowd back.
All of the animals reportedly returned to their bases safely after they were "pelted with glass bottles, rocks and fireworks", according to a Facebook post by the owner of the police dog that prompted a change in the law over prosecutions for harming police animals.
Rows of officers and vans were used to block the protesters from Bridewell police station, where a number of police vehicles had been set alight during violent scenes last Sunday.
Officers had previously urged people not to attend last night’s demonstration because of the risk of spreading COVID-19.
Friday’s protest – which was against the government’s Police, Crime, Sentencing and Courts Bill – had started peacefully, and the size of the crowd grew as the evening progressed.
The bill would give police in England and Wales more power to impose conditions on non-violent protests, including those deemed too noisy or a nuisance.
Those convicted under the proposed legislation could face a fine or a jail term.
Nine people were arrested in connection with last Sunday’s disorder in Bristol, while 15 others were held following a second protest on Tuesday night.
Earlier on Friday, the National Police Chiefs’ Council had warned violent protesters will "face the full weight of the law".
Martin Hewitt added: "I would ask people planning to protest this weekend to think carefully and consider whether joining a large gathering outside, in the midst of a pandemic, and potentially being near the scene of violence like we saw last weekend, is something that is safe for them as individuals to do."
He also claimed a number of people who attended the demonstration were "intent on causing violence and causing damage" – and those arrested came from "all over the United Kingdom".
Mr Hewitt went on to confirm that one of those who has been imprisoned following last Sunday’s unrest was someone already on bail for assaulting police officers.