Russian President Vladimir Putin is warning of preemptive strikes on terrorists. His announcement came shortly after prominent Chechen warlord, Shamil Basayev, claimed responsibility for the bloody school siege in Beslan two weeks ago. More than 320 hostages were killed in the siege.

Russian President Vladimir Putin's comments are the highest-level warning that Russia might launch pre-emptive strikes on terrorists.

Speaking in Moscow on Friday, the Russian leader said serious preparation to act preventively against terrorists is under way. If taken, the measures would be in strict accordance with the law and norms of the constitution and rely on international law, he said. Mr. Putin didn't specify whether attacks would happen at home or abroad.

Mr. Putin also ruled out any negotiations with the terrorists. He said every concession leads to a widening of their demands and multiplies the losses.

Shortly before the Russian President's announcement, the Kremlin's most wanted man, Chechen Shamil Basayev, published a statement on his rebel group's Web site. It said armed units of his Riyadus-Salikhin group carried out the attack on the school in southern Russia, which killed more than 330 people, half of them children.

Basayev also claimed responsibility for the downing of the two passenger planes and two bomb attacks in Moscow in recent months. One hundred people were killed in the attacks.

During the Beslan siege, the rebel leader said the group was demanding the withdrawal of Russian forces from Chechnya and Vladimir Putin's resignation. He said the hostage takers had promised to give food and water to their captives and to release the youngest children if the Russian side began to meet their demands.

The statement from the rebel leader vowed to continue the fight for Chechen independence by all possible means and said Russia had forced such a course on the rebels.

It was impossible to confirm whether the text on the Web site was genuine, but the Web site has been used by Basayev for claims of responsibility before.

Russia's federal security service's spokesman in Chechnya, Maj. Gen. Ilya Shabalkin, said the statement caused little surprise. According to Mr.Shabalink, the authorities had known "long ago" that Basayev was responsible for the attacks.