Police are investigating assaults on 40 officers and one member of the media at a riot in Bristol on Sunday.
Avon and Somerset Police said two further people, a 20-year-old man and a man currently refusing to provide details, had been arrested on suspicion of violent disorder and were in custody.
This brings the total number of arrests in connection with the disorder – which saw police officers injured, police vehicles set on fire and a police station attacked – to nine.
The riot followed a peaceful “Kill the Bill” protest in Bristol on Sunday, against the Government’s Police, Crime, Sentencing and Courts Bill, which will see the police handed new powers to tackle demonstrations.
A second protest against the Bill took place in the city on Tuesday, resulting in 14 arrests.
Chief Superintendent Carolyn Belafonte said the investigation into Sunday’s riot could be one of the largest in the history of Avon and Somerset Police.
“The fact we’re investigating 40 assaults on officers and a member of the media as the result of one incident shows the scale of wanton disorder which took place that night,” Chief Supt Belafonte said.
“Through painstaking work to examine more than two terabytes worth of digital footage, we believe we’re making clear progress to identify those responsible and anticipate further images will be released soon to the online gallery we’ve set up.
“One of the people we believe we’ve already identified is a suspect in the fire which destroyed a mobile community police station.
“We’d like to thank every member of the public who’s got in touch to provide footage, information or to pass on their well-wishes and kind thoughts.”
Around 3,000 people had attended a peaceful demonstration on College Green but events turned violent after about 500 people descended on Bridewell police station.
Police have released images of 17 people they want to identify following the protest on Sunday.
The force has received 210 submissions after appealing for members of the public to supply footage or information about those involved, as well as 68 calls to the control room.
Two officers taken to hospital during the riot were found not to have suffered broken bones.
Six men arrested on suspicion of violent disorder have been released under investigation, while a 28-year-old man appeared at Bristol Magistrates’ Court charged with possessing an offensive weapon.
On Tuesday, around 200 people gathered on College Green for a second night of protests.
Police requested mutual aid from neighbouring forces to assist in dispersing the gathering after attempts to encourage people to leave were unsuccessful, a police spokesman said.
Public order officers from Avon and Somerset, British Transport Police, Devon and Cornwall, Dorset, Dyfed-Powys, Gloucestershire, Gwent and Wiltshire were deployed to move protesters on at 10pm.
Police dog units, horses, the police helicopter and a police drone unit were also involved in the operation.
Many protesters left the area but a “significant number” gathered on Deanery Road and refused to disperse, Avon and Somerset Police said.
Fourteen arrests were made, with one of those detained also arrested for offences connected to Sunday’s protest.
Chief Superintendent Claire Armes said: “After the scenes of violence witnessed in the city at the weekend, it was necessary to bring in additional resources from our neighbouring forces to ensure the protest was safely brought to a swift conclusion.
“Throughout the operation officers continued to urge protesters to move on – at no time were they contained – but there came a time when enforcement was necessary as gatherings are still not permitted.”
John Apter, national chairman of the Police Federation of England and Wales, said officers in Bristol felt “under siege” following the second protest in the city.
“I really feel for my colleagues in Bristol,” Mr Apter told the BBC.
“There is a sense that you really feel under siege. And for some, whatever they do is not enough and for others, it’s too much.
“This was on an evening where the vast majority of the country were remembering those many thousands of people who have been lost to this horrible virus, so it was not good scenes to see, and this was on the back of the most horrendous violence that we’d seen on Sunday evening.
“So my colleagues are battered and bruised, in some cases physically. We’ve got a number of officers who were injured on Sunday evening, some very seriously. This is completely unacceptable, completely unacceptable.”
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.
Home Secretary Priti Patel criticised the “criminality and violent behaviour” seen during the protests in Bristol.
“We live in an open society and a democracy so the principle to protest and to have your voice heard is absolutely crucial,” she told BBC Breakfast, “but there is no acceptability at all for criminality, thuggish behaviour and the type of violent scenes we’ve seen over recent evenings, they included the most appalling assaults and criminal attacks on police officers, there’s a fundamental difference between the two.”