The head of Russia's parliamentary commission investigating last year's bloody Beslan school siege says the crisis could have been prevented if local authorities had followed orders to tighten security.

Alexander Torshin told Russian lawmakers local authorities in North Ossetia, where Beslan is located, failed to carry out instructions given by Russia's Interior Ministry to strengthen security around educational institutions on the first day of school.

Gunmen demanding a withdrawal of Russian forces from Chechnya held more than a 1,000 hostages for three days. The stand-off ended in a series of explosions as security forces stormed the building. More than 330 people, mostly children, were killed.

Tuesday, Russia's deputy prosecutor-general Nikolai Shepel said security forces acted properly to end the siege.

A committee of Beslan mothers has criticized authorities for using flame-throwers and tanks, which caused the roof to collapse on escaping hostages.

Some information for this report provided by Reuters, AFP and AP.