The RUC in Derry said yesterday that it was concerned about the condition of an inspector who was seriously injured during disturbances on Sunday night.
The inspector suffered a skull fracture when a stone thrown by a loyalist youth struck him during rioting near the village of Tullyally.
A gang of loyalist youths attacked police lines with stones and petrol-bombs when officers were called to the village following reports that a car had been set on fire.
The violence was condemned by Supt Stewart Tosh, who said that 12 people had been arrested as a result of it.
"Our thoughts are with the family of our colleague, who is seriously ill in hospital", he said. "His condition is being constantly assessed and we are very concerned for him. It is a serious injury. I cannot in any way find any excuse for this type of behaviour. There can be no justification for the violence and disruption which took place in several locations in the Waterside overnight.
"I would appeal to people to remain calm and be responsible. We respect the right of peaceful protest, but nothing can justify the violence and damage caused to property by petrol-bombing. I can tell the public that every endeavour will be made to keep roads open and that my officers will deal with the pressures and tensions on them professionally and responsibly."
The violence was also condemned by the Mayor of Derry, Alderman Joe Miller, who is a former policeman, and by the city's Grand Orange Lodge. A lodge spokesman said that his members deplored the violence. "We would point out that the Grand Lodge of Ireland, ourselves and particularly the officers of the Portadown District have requested emphatically that no acts of violence or destruction of property should be perpetrated on their behalf.
"Appeals have been made by the Grand Master of Ireland and by the Portadown District Master for no such acts and the City Grand Lodge would fully support this. We appeal for those involved to act in a responsible, peaceful and legal manner at all times. To do anything other is of no assistance to the brethren of Portadown and is purely playing into the trap of our opponents."
Six men appeared in Belfast Magistrates' Court yesterday arising out of overnight rioting in Belfast, Newtownabbey and Carrickfergus. The charges included riotous behaviour, possessing an offensive weapon, disorderly behaviour and receiving cigarettes looted from a petrol station at O'Neill Road, Newtownabbey.
One man was given a suspended jail sentence of three months and another was fined £75. Three others were remanded in custody and a teenager who was granted bail was ordered to stay in his home between 7 p.m. and 7 a.m.