Baton rounds were fired during rioting in north Belfast for the first time in almost three years in Northern Ireland, it has emerged.
Rioters attacked police with petrol and blast bombs
The trouble began when nationalists attacked police after an Orange Order parade passed the Ardoyne shops area.
Police fired the new baton rounds, known as attenuated energy projectiles, which were introduced last month.
About 80 officers were injured, one seriously during Tuesday's trouble in which petrol and blast bombs were used.
It is understood dissident republicans linked to the Continuity IRA were responsible for the most serious attacks. Several arrests were made.
The new style baton rounds are intended to present a reduced risk of causing serious or fatal injuries.
Baton rounds were last used in Northern Ireland in September 2002.
Petrol bombs and three blast bombs, as well as bottles and bricks, were thrown at the police during disturbances on Tuesday.
One police officer was seriously injured and has been undergoing surgery in hospital. The extent of his injuries are not clear, but his condition is not believed to be life threatening.
The most serious violence against the police was in the Brompton Park area. A car was hi-jacked and burned and police used a water cannon on rioters.
Earlier on Tuesday, in agreement with police, 15 protesters were allowed to stand on a wall overlooking the route as the Orangemen passed holding aloft a banner saying 'make sectarianism history'.
Speaking on Wednesday, Sinn Fein North Belfast assembly member Gerry Kelly said lives could have been lost in the disturbances and that dialogue was "fundamental".
"To take a position as a political leader not to speak and for the Orange Order to take a position not to speak to residents or indeed to political representatives is one way of going absolutely nowhere," he said.
SDLP policing spokesman Alex Attwood said the police "generally behaved properly and proportionately, faced with blast bombs falling among the media, local representatives and people, and the police themselves".
"This needs to be faced up to, rather than trying to misrepresent the full nature of the police response and the true facts of what transpired after an unwelcome and offensive Orange parade had passed through."
Superintendent Gary White, who was in charge of the police operation, said the violence had clearly been premeditated.
Council workers have been clearing debris from roads after the riot
"We've used water cannon and various other tactics, and we retain the right to use whatever tactics are necessary when we're faced with a lethal threat," he added.
Local priest Father Aidan Troy, who had worked closely with the police, politicians and community leaders in a bid to avert trouble, said what happened was deeply disappointing.
Speaking after Tuesday's rioting, the DUP's North Belfast MP Nigel Dodds said republicans either had no control of the situation or no desire to exert that control.
"I have to say that this morning the use of an illegal protest on the street, sanctioned by Sinn Fein, was not a good thing to do because it set the trend for further illegality tonight," he said.
In a statement, the Orange Order called on the Parades Commission to ban future protests at Ardoyne.
Police were attacked with petrol bombs
Ulster Unionist leader Sir Reg Empey said an overall solution needed to be found on the parades issue and called on the secretary of state to begin talks in the autumn.
"We can't allow what is an issue of cultural rights to be turned into a political football, and there has to be a consensus on how this is dealt with," he said.
Meanwhile in Londonderry, seven police officers were injured as 52 petrol bombs were thrown during rioting early on Wednesday.
Eleven people were arrested by police, who are trying to identify those involved in the trouble in both the Cityside and Waterside areas.
The Twelfth of July Orange Order parades mark the victory of the Protestant Prince William of Orange over the Catholic King James II at the Battle of the Boyne in 1690.