Police had no intelligence to suggest there would be violence at a flag protest in Belfast, the officer leading the operation admitted today.
Rioting loyalists injured 15 PSNI members, two council security guards and a press photographer when they tried to smash their way into Belfast City Hall after a controversial vote on the Union flag.
Chief Superintendent Alan McCrum said: "A diverse crowd, of up to 1,500 at the peak of the protest, consisting of men, women, young people, mothers with children in buggies and wheelchair users, gathered at the back of City Hall.
"Police had no definitive intelligence to suggest that there would be any violence and given the diversity of the people protesting, the operation had to be managed very carefully."
This morning the Union flag was removed from City Hall for the first time in more than a century. The move brings the building into line with Stormont's Parliament Buildings where it only is flown on designated days.
Police were pelted with missiles including fireworks, bricks, bottles and stones. A number of protesters also brought bolt cutters to break a lock on the iron gates of City Hall and at one point a masked mob tried to kick down the back door of the building.
Politicians and community workers across Belfast have claimed the violence was orchestrated through social networking sites such as Facebook and Twitter.
Sinn Fein Policing Board member Gerry Kelly, who was inside City Hall at the time of the riot, slammed the policing operation as inadequate.
He claimed officers were over-run and ill-equipped when the protest turned ugly.
Policing Board Chairman Brian Rea also raised questions about the preparedness of the PSNI ahead of the protest.
Mr McCrum defended his decision to deploy community beat officers and not the riot squad to monitor the volatile situation.
He said: "Neighbourhood officers who had been positioned outside the gates of City Hall were attacked and these officers were then replaced with riot police who were located a short distance away on the other side of the road.
"Officers had also been positioned inside the quadrant area at the back of City Hall to prevent those individuals who breached the gates from entering the building.
"This disorder was completely disgraceful. There is no excuse for vandalism and thuggery in a democratic society. People have the right to lawful protest, but democracy has a right to be protected."
The trouble spread to parts of east Belfast where a Catholic Church and homes in the nationalist Short Strand came under attack. Attempts were also made to hijack a double decker bus.
Three people, aged 17, 18 and 22, have been arrested in connection with the disorder.
Condemnation of the violence has been led by the DUP First Minister Peter Robinson whose party had vehemently opposed any changes to the City Council's Union flag policy.
Mr Robinson described the disorder as inexcusable but said: "The decision to pursue the removal of the flag from City Hall and other council buildings, despite warnings of the likely consequential impact on community relations, was foolish and provocative. Those who talk most about building community relations have by their actions in the council substantially damaged relations across the city."
Nationalists had wanted to remove the Union flag permanently from Belfast City Hall. However, they voted in favour of a proposal from the non-sectarian Alliance Party that allowed it to be flown on 17 designated days throughout the year.
The divisive and emotive issue is due to be discussed again next month when a separate proposal to have the Union flag flown over the cenotaph in the grounds of City Hall is brought forward.
Tony McCusker, chairman of the Northern Ireland Community Relations Council, said: "In the interests of good community relations the Community Relations Council supported the compromise proposal to fly the Union flag on designated days only. This is the practice at Stormont and many public buildings in Britain. It need not be seen as a dilution of Britishness."
A crowd of about 100 loyalists picketed the office of East Belfast MP Naomi Long.
They pinned Union flags as well as red, white and balloons to lampposts close to the Alliance Party office on Upper Newtownards Road.
The protest was organised to demonstrate opposition to the stance taken by Alliance Party councillors in Belfast over changes to the flags policy.
Police were at the scene but the situation remained calm.
Sinn Fein said North Belfast MLA Gerry Kelly received a death threat in the aftermath of the City Hall flag row.
A spokesman said the threat was received at his Antrim Road constituency office.
"The threat obviously follows in the aftermath of last night's attack on democracy at the Belfast City Hall by loyalists.
"The people who made the threat should understand that I nor any of the other Sinn Fein representatives will be deflected from pursuing equality in the city of Belfast or anywhere else."