A top Russian prosecutor says he will not open a criminal investigation against security forces involved in last year's deadly hostage crisis at a school in the southern city of Beslan.

Deputy Prosecutor General Vladimir Kolesnikov Thursday rejected arguments made by relatives of the victims.

Relatives blamed security forces for using flame-throwers and starting a fire that caused the roof to collapse as they moved on the school, seized by Chechen militants.

They said the rescue attempt was chaotic and caused many of the 331 deaths, most of them children.

Children and teachers were held for three days as hostage takers demanded Russian forces leave Chechnya.

Some information in this report provided by AP and AFP.