Three men were arrested in connection with a blast bomb thrown as Catholic children went to school under armed guard during the third day of protests in north Belfast.
Two police officers received shrapnel wounds in the blast bomb attack and two others were treated for minor injuries as violence erupted in the Ardoyne area.
The arrests came as Northern Ireland Secretary John Reid decided to cut short his summer holiday to deal with the deteriorating security situation in the province following the dispute at the Holy Cross School.
The so-called Red Hand Defenders, a cover name for the Protestant paramilitaryUlster Defence Association said it was responsible for the blast bomb attack.
Billy Hutchinson, a leading figure in the Progressive Unionist Party which has close links with the loyalist paramilitaries, condemned the attack.
Many of the youngsters being escorted to the school by parents and friends down a cordon created by police and soldiers for their protection burst into tears.
One woman appeared to faint after hearing the blast, but none of the children were injured.
RUC Assistant Chief Constable Alan McQuillan insisted today the force would maintain its security operation in the Ardoyne to enable the children to get to school.
Amid accusations from the unionist Lord Mayor of Belfast, Jim Rodgers, that police were making the situation worse, he said police had to be there to give the children their right to go to school.
Referring to the naked sectarianism in the area which erupted into more violence last night, he said: "What we had last night was mobs on both sides attempting to attack the homes of the other community with the police and the army standing between them.
"Let's be quite clear, this is not an attack on us, we are incidental to them, they are simply trying to get at the other side."
He said the vast majority of the violence came from the loyalist side.
"We have here basically people who want to engage the other side, who want to fight the other side and we are trying to stop them."
Mr McQuillan said police had watched and supported the attempts to resolve the issue during the summer and had a small security operation in place for the first day of term on Monday.
"What was the result ? We had vile abuse thrown at children, we had missiles and stones thrown at children and then police officers attacked as well.
"We had to go in with an operation of this scale to protect these children who have a right to walk up that road to go to school.
"We have no great wish to be there but we have to be there to protect them and we will be there."
Mr Rodgers also complained he had been manhandled and abused by police when he went to the scene of the school trouble on Monday to try to calm the situation.
"I had been speaking to people on both sides of the divide as well as the security forces. I went to try to reason with some loyalist demonstrators and on my way back a police officer would not let me through," he said.
"He gave me a mouthful and pushed his plastic riot shield into my chest on two occasions. As Lord Mayor or an ordinary citizen I don't think this is acceptable."
Mr Rodgers said he had warned police their security operation was "the height of madness" and making the situation worse.
Condemning the violence unreservedly he said he believed it would be a major step towards stopping the trouble if the protesters called off their demonstrations and the children's parents took the alternative longer route to school through the back entrance while efforts were made to find a solution to the dispute.
"We must pull back from the brink, this is not doing our city any good," he said.
Responding to Mr Rodgers' complaint about police action, Mr McQuillan said if it had happened he deeply regretted it and urged the Lord Mayor to make a formal complaint.
"I want my officers to behave properly and if they misbehave let's have it investigated. There is an independent agency to do that."Reuse content