The world will watch the Protestant protest outside a Catholic school in north Belfast with disbelief, a Northern Ireland Office Minister has said.
Ms Jane Kennedy, the NIO Security Minister, said the "disgraceful" scenes could bear no justification whatsoever.
"It is impossible to imagine the traumatic effects that today must have had upon the young children trying to go to school," she said.
"The eyes of the world are, once again, looking at the situation here. Nobody can understand what is going on here. How can subjecting four-year-old children to such verbal and physical abuse possibly advance the cause of a community that has a grievance?"
She added: "Nobody can understand it, you and I can't understand it and the watching world looks on with disbelief. This is a bad day for the standing of Northern Ireland in the eyes of the world." The SDLP Assembly member for North Belfast, Mr Alban Maginness, said the protest outside the school was "unacceptable and an affront to common decency". He called on the DUP MP for the area, Mr Nigel Dodds, to condemn the protests and said his silence had been "deafening".
"You have to show leadership to the whole community. You cannot represent one section of the community, you must represent the whole community and he must come out and say it is immoral and wrong," said Mr Maginness.
Mr Gerry Kelly, the Sinn Fein Assembly member for north Belfast, said Mr Dodds had found every excuse possible not to answer the simple question of whether the protest was right or wrong and had not called for it to end.
"His comments today on the blockade of the Holy Cross School proves beyond doubt his refusal to acknowledge the rights of the nationalist community," he said.
Ms Margaret McClenaghan, a Sinn Fein councillor, later claimed the RUC allowed loyalists through their lines in the afternoon. She said this was typical of its "half-hearted attitude" to dealing with the protesters.
The Ulster Unionist Assembly member for the area, Mr Fred Cobain, called for the dispute to be resolved through dialogue. He said all parents would be distressed by the scenes outside the school. "However, it must be said this incident is more a symptom of the problems in the area, rather than the cause."