Medical workers began identifying more than 100 bodies burned beyond recognition in the blasts which ended the crisis in Beslan, North Ossetia. The leader of the province promised to sack the regional government.
Over 1,200 people were taken hostage and at least 326 were killed and 727 wounded, Prosecutor General Vladimir Ustinov said, revising the death toll down from 335. Only 210 bodies have been identified.
"As for launching pre-emptive strikes on terrorist bases, we will carry out all measures to liquidate terrorist bases in any region of the world," General Yuri Baluevsky, chief of Russia's general staff, said, according to Russian news agencies.
"However, this does not mean that we will launch nuclear strikes."
In 2002 President Vladimir Putin accused neighbouring Georgia of harbouring Chechen rebel bases and said this gave Moscow the right to strike at rebel suspects beyond Russia's borders.
In June, a court in Qatar sentenced two Russians to life imprisonment for killing a Chechen rebel leader, Zelimkhan Yandarbiyev, in the Gulf state. The judge said they had been acting on orders from Moscow.
The FSB security service announced the 8.5m reward for information leading to the "neutralisation" of Aslan Maskhadov and Shamil Basayev, two Chechen separatist leaders who are household names in Russia after a decade of conflict in the mainly Muslim southern province.
At the scene of the siege, medical workers began the grisly task of identifying more than 100 bodies burned beyond recognition in the explosions which ended the crisis.
The broadcast on Russian television of graphic footage filmed by militants inside the school added to the horror as Beslan residents prepared to bury more dead.
The pictures showed the school gym littered with what appeared to be bombs and bomb-making equipment and crammed with hostages, watched over by around six of the masked militants, one of whom was heard murmuring, apparently in an Arabic prayer.
One captured suspect said the hostage-takers numbered around 30, including two women, said General Ustinov. At the start of the siege, some asked their leader why they had seized a school. He shot one of the waverers dead and later killed two more by detonating their explosive belts, to frighten the others.
General Ustinov said the militants later tried to rewire their bombs but one exploded, triggering the storming of the school something security analysts have slammed as a bungled operation.
Russia's Izvestia daily, citing troops who took part in the assault, said four of the hostage-takers were captured, including a woman.