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The victims of the siege.

The Beslan school siege (also referred to as the Beslan school hostage crisis or Beslan massacre) started on 1 September 2004, lasted three days, involved the illegal imprisonment of over 1,100 people as hostages (including 777 children), and ended with the deaths of at least 334 people. The crisis began when a group of armed Islamic militants, mostly Ingush and Chechen, occupied School Number One (SNO) in the town of Beslan, North Ossetia (an autonomous republic in the North Caucasus region of the Russian Federation) on 1 September 2004. The hostage-takers were Riyad-us Saliheen, sent by the Chechen warlord Shamil Basayev, who demanded recognition of the independence of Chechnya, and Russian withdrawal from Chechnya. On the third day of the standoff, Russian security forces stormed the building with the use of tanks, incendiary rockets and other heavy weapons. As of December 2006, 334 people (excluding terrorists) were killed, including 186 children.

The event led to security and political repercussions in Russia; most notably, it contributed to a series of federal government reforms consolidating power in the Kremlin and strengthening of the powers of the President of Russia, Vladimir Putin. As of 2016, aspects of the crisis in relation to the militants continue to be contentious: questions remain regarding how many terrorists were involved, the nature of their preparations and whether a section of the group had escaped. Questions about the Russian government's management of the crisis have also persisted, including allegations of disinformation and censorship in news media, whether the journalists who were present at Beslan were allowed to freely report on the crisis, the nature and content of negotiations with the terrorists, allocation of responsibility for the eventual outcome, and perceptions that excessive force was used.

The European Court of Human Rights (ECHR) in a 2017 ruling criticized Russia for not taking sufficient precautions before the event, and for using excessive lethal force when concluding the siege which violated the "right to life".