The European Court of Human Rights has condemned Russia over its failure to protect the hundreds of people who died when Chechen militants took over a school in Beslan in 2004.
The court ruled that serious failings by the Russian authorities meant that the victims' right to life was violated, and ordered Russia to pay €3 million in reparations.
The Beslan school siege began when 30 separatist gunmen took more than 1,100 hostages in School Number 1 in September 2004. Russian special forces stormed the building in a blaze of gunfire after 52 hours, and the hail of bullets, explosions and fire that followed killed 334 people, including more than 180 children.
The episode was one of the darkest in Vladimir Putin's long tenure in Russia and some residents still blame him for the official response.
On Thursday morning, the ECHR ruled unanimously that Russia had failed to prevent the attack, despite intelligence services having "specific information of a planned terrorist attack in the area, linked to an educational institution".
The judges also found there were "serious shortcomings" in the security operation to end the siege, which culminated in there not being a single fire engine at the scene when the raid occurred.
And they ruled that the use of tanks, grenade launchers and flame-throwers to break the hostage situation "contributed to the casualties among the hostages" and was not justified in the circumstances.
The case was brought by 409 people, including those injured and taken as hostage in the attack itself, as well as family members of those killed.
The Kremlin described the court's conclusion as "unacceptable", and a spokesman said Russia could not agree with its ruling.
