Russia is prepared to launch pre-emptive strikes against "terrorist bases" in any part of the world, Russian news agencies quoted Russia's Chief of Staff Yuri Baluyevsky as saying Wednesday. 

"With regard to preventive strikes on terrorist bases, we will take any action to eliminate terrorist bases in any region of the world. But this does not mean we will carry out nuclear strikes," Baluyevsky was cited as saying.

"Military action is the last resort in the fight against terrorism," he stressed.

Baluyevsky's statement came after last week's hostage-taking tragedy in a southern Russian school which left at least 338 people, half of them children, dead.

The school siege followed a string of attacks blamed on Chechen rebels, including the downing of two Russian passenger planes and a suicide bombing in central Moscow.

US$10m for rebel leaders clues

The Russian Federal Security Services (FSB) offered a reward of up to 300 million rubles (over US$10 million) for information that will help it hunt down Chechen rebel leaders Shamil Basayev and Aslan Maskhadov, the Interfax News Agency reported.

The FSB accused Basayev and Maskhadov of committing inhuman acts resulting in irreparable losses for Russia over the past several years.

The FSB said in a statement that it will pay the reward for information about the Chechen warlords' whereabouts which would lead to their neutralization.

The statement said the FSB guarantees the informants' anonymity and security.

The FSB has opened around-the-clock phone service in Moscow, Chechnya and other Russian regions for those wishing to provide such information, the statement said.

Basayev and Maskhadov are accused of being behind last week's school siege.

The offer of reward was announced amid Russia's investigation into the hostage-taking raid.

The Chechen pair already had bounties on them after Ramzan Kadyrov, son of the late Chechen President Akhmad Kadyrov, offered in December to pay US$5 million for Basayev and US$50,000 for Maskhadov, saying Basayev posed a much graver threat.

Earlier on Tuesday morning, the Russian Foreign Ministry said in a statement that it would step up its efforts to persuade Britain to extradite Maskhadov's spokesman Akhmed Zakayev, who was granted asylum last year.

Maskhadov aides have denied that he had any role in the latest attacks. However, Basayev has made no comments.