Russian prosecutors investigating last year's Beslan school siege say the authorities made no mistakes during the crisis in North Ossetia.
Relatives of the dead say they do not trust the authorities
Relatives of more than 330 people who died in the siege accuse the security services of incompetence.
They say the police who stormed the school should shoulder the blame for as many deaths as the hostage-takers.
An earlier report by the local parliamentary commission did find the security services had been incompetent.
The BBC's Artyom Liss in Moscow says the prosecutors' report, released on Monday, will probably infuriate relatives of those who died in Beslan - but it does not come as a surprise.
In September 2004, more than 300 people were killed when mines planted by the hostage-takers inside the school began to explode and police and troops stormed the building.
Since then people in Beslan have demanded that the authorities be called to account.
The prosecutors' view of events is very different to the findings of the local parliamentary commission.
Deputy Prosecutor-General Nikolay Shepel told Interfax news agency the security forces had all acted strictly within the law, and a reconstruction of the events did not uncover any actions that could have provoked the tragedy.
"According to the conclusions of the investigation, the expert commission did not find ... any infringements which could have a causal link to the harmful consequences which resulted from the terrorist act in Beslan," he said.
But, Mr Shepel added, the experts had concluded that the existing system for preventing terrorism did not provide full protection for the country's population.
"This manifests itself in an inability to discover, warn of and prevent terrorist attacks in good time," he said.
Our correspondent says that for victims of the siege all this is little consolation. Dozens of them, who have formed the group known as the Mothers of Beslan, have already accused the prosecutors of trying to whitewash the generals responsible.
They say they do not trust the authorities and promise to continue their own investigation.