Fifty six police officers were injured during loyalist riots in Belfast city centre in a night of chaotic violence that Northern Ireland's Chief Constable has described as mindless anarchy.
Protesters who ran amok through central streets and attacked police with missiles, including scaffolding poles and paving stones ripped up from a main shopping district, have scarred the city's reputation, Matt Baggott said.
The region's top officer issued a challenge to politicians and community leaders to act like "statesmen" in the wake of the disorder and unequivocally condemn those responsible.
The violence erupted in the Royal Avenue area, a usually busy commercial street close to City Hall, as more than a thousand loyalist demonstrators gathered to protest at the republican rally to mark the introduction of internment without trial in Northern Ireland during the Troubles.
Four officers required hospital treatment. Police, who deployed water canon and 26 plastic baton rounds in a bid to quell the unrest, have arrested seven people so far, but have warned that many more will follow.
"I know that 99%, if not more, of the population will stand with me in utterly condemning those who scarred the reputation of our beautiful city last night," said Mr Baggott.
"Those people had no intention of peaceful protest, they lack self respect and they lack dignity."
Mr Baggott, who warned that the "prisons would be bulging" once the police had identified and arrested those responsible, added: "The only voices we should hear now are those unequivocally condemning the violence and supporting fully the actions of the police and the rule of law and I don't want to hear any excuses for the disgraceful scenes that took place last night, because quite frankly there aren't any."
The trouble broke out as the city hosts thousands of international visitors attending the World Police and Fire Games.
Northern Ireland Secretary Theresa Villiers condemned the rioters.
"Last night's violence and attacks on police officers were shameful," she said.
"After success for Northern Ireland this summer as host to both the G8 Summit (in Co Fermanagh in June) and the World Police and Fire Games, disorder on the streets is a hugely regrettable step backwards."
Last night's violence spread from the Royal Avenue area as the Anti-Internment League parade, which was sanctioned by the Parades Commission adjudication body, approached from north Belfast.
Some direct clashes with loyalists and republicans ensued close to the entrance to the unionist Shankill Road, and police said they came under attack from both sides, but officers have stressed that loyalist protesters were responsible for the vast majority of the violence.
A number of parked vehicles were set on fire in the nearby North Street area and police have revealed that some rioters took to the roof tops of city buildings and houses and tried to set them on fire.
The parade did not pass down Royal Avenue as intended. After a significant delay, it did finally proceed along the outskirts of the city centre and onward to west Belfast.
Police stressed that the parade was not re-routed by their officers with organisers voluntarily deciding to take another road.
The Parades Commission had authorised the parade and permitted six notified protests, including one by the Orange Order.
Assistant Chief Constable George Hamilton heavily criticised those who arranged the demonstrations.
"There was absolutely no organisation, no co-ordination, no leadership around any of those protests," he said.
The officer said it was clear that a large number of the protesters arrived with "violent intent".
"There was no attempt whatsoever, that we could see, of any organised or coordinated protest activity in keeping with that which had been notified to the parades commission."
Mr Hamilton characterised the violence in Royal Avenue as "very severe".
"There were all sorts of weapons and equipment being used against police, including scaffolding, masonry, people were pulling up the paving stones from the busiest shopping precinct in Belfast and were destroying our city and taking that masonry and throwing it at our police officers who put their lives on the line to try and keep people safe.
"There was nothing lawful about this protest, there was nothing peaceful about it - it was sheer thuggery."
The assistant chief constable said officers had almost cleared Royal Avenue of protesters when the parade organisers decided to take another route.
"It's perhaps understandable that they would do that," he said.
"But the police did not re-route the parade away from Royal Avenue and in fact we were within minutes of having Royal Avenue cleared to allow the parade go through."
Mr Hamilton added: "We would call on anyone with any influence to stand up and be counted, actually to show some leadership around what is a difficult set of circumstances for us, but we actually need those with influence within the community to use that for good, so that we don't resort to the violent scenes that we saw last night."
Mr Baggott said it was too early to establish whether there was paramilitary orchestration of the violence.
Last night's disorder came after eight officers were injured when trouble flared at a republican anti-internment bonfire near the city centre on Thursday night. Eight people were arrested and at one point, as violence spread to north Belfast, officers were attacked by a man wielding a sword.
Less than a month ago, parts of Belfast were consumed by rioting, predominantly loyalist, triggered when Orangemen were prevented from parading past the nationalist Ardoyne area in the north of the city.
Parading tensions have also spread elsewhere in Northern Ireland with major controversy surrounding a planned Sinn Fein-backed commemoration event in the Co Tyrone town of Castlederg tomorrow for local IRA members killed during the conflict.
Former White House special envoy Dr Richard Haass is due to chair cross party talks in the autumn in a bid to find a resolution to the parading disputes and other outstanding issues as yet settled during the peace process.
Mr Baggott said the bravery of his officers had saved lives last night.
But Ulster Unionist Assembly member Michael Copeland, a representative from East Belfast, has claimed he and members of his family were assaulted by police in Royal Avenue.
Asked about that incident and any other claims of police heavy handedness, Mr Baggott urged people with complaints to contact the Police Ombudsman's office.
But he added: "You saw the scaffolding poles, the metal gratings from the drains, the breaking up of paving slabs, people on roof tops trying to burn houses, people trying to set light to vans and cars and trying to drive them at police lines. You know something - if you are in the middle of a riot and you choose to be there, I have little sympathy. If anybody has any concerns about police actions they can report to the ombudsman - I won't stand over bad behaviour - but you saw the magnificent way that police officers reacted last night, and their courage - that is the message that needs to go out today."
The chief constable said the violence had cast a shadow over the Police and Fire Games, but he insisted that the positive memories of the event would endure longer than the thuggery of rioters.
"Last night we had a street with intense violence, we had another street next door with people enjoying themselves," he said.
"It's like a battle between the good and the bad, isn't it. I can assure you as far as we are concerned, we are doing everything we can to make sure that good works, because young people deserve a better future in this place than what was offered last night by the mindless anarchy on the street."
Mr Baggott urged leaders to press home the message that politics was the only way forward.
"The only people they (the rioters) are damaging is themselves," he added.
"It is their communities that are going to be condemned to another decade without hope, if not longer, this is only damaging their own community and that's the sort of message our politicians need to be getting out there."
Ulster Unionist leader Mike Nesbitt said rioters threw a half brick at him while he was trying to speak to officers in Royal Avenue last night.
"I often hear calls for leadership on the ground," he said.
"That is why I was on Royal Avenue last night, but it is impossible to offer anything constructive while under physical attack. I stress it was a minority who engaged in violence, there were many in that crowd who were there for lawful protest."
Mr Nesbitt said those loyalists who engaged in violence were aiding a republican cause.
"The violence witnessed in Belfast last night was wrong and I condemn it all, whoever was responsible, and it certainly did not come from a single group," he said.
"I deeply regret the injuries sustained by police officers in the lawful execution of their duty and wish them all speedy and full recoveries. Violence against the police from those belonging to the Protestant Unionist Loyalist community is not only wrong, it is also playing into the hands of Irish Republicanism. It removes the focus from the offensive nature of their attempt to re-write history and excuse the terrorism that blighted our country for decades, and still does."
Stormont's Justice Minister David Ford said there could be no excuse for last night's rioting.
"Violence is wrong and no cause, no dispute, no disagreement can justify it," he said.
"The scenes of loyalist protesters attacking the police service will quickly replace the positive images many have worked hard to deliver in recent weeks.
"Some individuals and groups may not agree with determinations from the Parades Commission, but they do have the weight of the law behind them.
"Until we come up with an alternative way to deal with contentious parades the police are required to put themselves in the front line to uphold those determinations.
"There were no winners last night, but I know there will be losers amongst the retailers and communities directly affected. I am confident that over the coming days and weeks those involved in the violence will be the main losers as the police begin gathering evidence and carrying out arrests.
"I thank the officers who were on duty in Belfast and send my best wishes to those injured."