At least seven people have been arrested in connection with the violent scenes that marred a "Kill the Bill" protest in Bristol, which saw a police station attacked, officers injured and vehicles set alight.

Six of the seven were arrested for violent disorder and one was detained for possession of an offensive weapon.

The Avon and Somerset police and crime commissioner said "many more" would be arrested in the coming days as officers examined a large amount of CCTV footage from last night's riot.

Twenty police officers were injured, two seriously, when what started as a non-violent demonstration turned violent after hundreds of protesters descended on the New Bridewell police station.

Two of these injured were treated in hospital after suffering broken ribs and an arm. Both have since been discharged.

Police said between 2,000 and 3,000 people had gathered at College Green to protest against the UK government's Police, Crime, Sentencing and Courts Bill, which will see the police handed new powers to tackle demonstrations.

Andy Marsh, chief constable of Avon and Somerset Police, said the demonstration had been "hijacked" by several hundred "extremists".

"I believe the events of yesterday were hijacked by extremists, people who were determined to commit criminal damage, to generate very negative sentiment about policing and to assault our brave officers," he said.

"Officers were very patient. From the initial gathering of around 2,000 to 3,000, which was more than we anticipated, there were about 50 officers engaging with those present and encouraging them to disperse. Many were complying, in fairness.

"There was a hardcore of serious criminals hidden within those 3,000 people - perhaps 400 or 500 people - and we certainly didn't trigger this.

"The officers were incredibly patient, incredibly professional and I pay tribute to them."

Mr Marsh said 12 police vehicles were damaged, including two that were set on fire, and "significant damage" was caused to the New Bridewell police station.

"I'm incredibly saddened by the dreadful scenes we saw here," he said.

"Officers were pelted with stones and missiles and fireworks and it was a terrifying situation for them to deal with.

"We have 20 officers injured, two of them seriously, and I spoke to one of them in hospital.

"Thankfully both officers have been released from hospital and are with their families.

"All of those assaulted were incredibly shocked, some of them were beaten around the head with sticks, hit with missiles."

UK Prime Minister Boris Johnson has condemned the scenes that marred a "Kill the Bill" protest as "unacceptable".

Police said seven people had been arrested, six for violent disorder and a seventh for possession of an offensive weapon, following Sunday night's riot.

Speaking to broadcasters at BAE Systems in Preston, Mr Johnson said: "I think all that kind of thing is unacceptable and the people obviously have a right to protest in this country.

"But they should protest peacefully and legally."

Home Secretary Priti Patel described the scenes as unacceptable and said "thuggery and disorder" would never be tolerated.

Bristol mayor Marvin Rees, who said he had "major concerns" about the government's Bill, condemned the violence, but said the disorder would be used to justify the legislation.

Sue Mountstevens, police and crime commissioner for Avon and Somerset, said seven people had been arrested so far and there would be "many more" detained.

"It's disgraceful and outrageous. Police officers went to work yesterday, and some have returned home via hospital battered and bruised," she said.

"There will be warrants, there will be arrests and police will be checking on the CCTV. There will be further arrests in the next few hours and days.

"I believe there have been seven arrests so far and there will be many more."

Workers clean up on the streets of Bristol this morning after the protest last night

The Police, Crime, Sentencing and Courts Bill would give the 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 jail.