The PSNI has claimed that dissident republicans tried to cause deaths by using nail bombs during riots in Belfast last night.
Earlier, Taoiseach Bertie Ahern said yesterday's disturbances in Northern Ireland would have been far worse but for the efforts of local community leaders.
He praised leaders for their 'Trojan' work in managing events in the streets.
Mr Ahern said it was regrettable that plastic baton rounds were fired by the PSNI for the first time in three years.
He told journalists that those involved in the Orange Order march in Derry were to be praised for their efforts and that a potentially dangerous stand off in Dunloy, Co Antrim, had also been averted.
The Taoiseach said violence in Ardoyne in Belfast had probably become inevitable and could have been far worse.
PSNI says officers hurt
Earlier, the PSNI said around 80 police officers were injured, one seriously, during trouble in north Belfast last night as an Orange parade returned past Ardoyne shops.
A police spokesman said about seven civilians, including two journalists, had also been injured and several arrests were made for public order offences.
The Sinn Féin President, Gerry Adams, claimed the police were largely to blame for what had occurred, but the PSNI rejected the criticism.
In the violence, groups of nationalist youths became involved in clashes with PSNI officers.
In a repeat of what happened last year, tempers snapped when through a gap in the huge temporary security screen nationalists caught sight of loyalists returning home through their area after a day's marching.
Several dozen nationalists pelted the police with stones, bottles and petrol bombs and set fire to a hijacked car.
Three blast bombs were thrown in the direction of the police, injuring several officers and a BBC journalist.
During two hours of exchanges the police used water cannon, spraying rioters, stewards, would-be peacemakers and onlookers.
Senior members of Sinn Féin and SDLP politicians had worked during the day to keep the situation calm.
Several Sinn Féin politicians took petrol bombs off the masked youths and they also retrieved a hijacked car.
