MOSCOW, May 12 (Reuters) - Two rebel suicide bombers drove a truck packed with explosives into a government building in the north of Russia's separatist-minded Chechnya on Monday, killing 40 people and wounding many more, officials said.
The blast in the town of Znamenskoye, north of the regional capital Grozny, was the most serious rebel attack since a Kremlin-organised constitutional referendum in March anchored the Muslim territory firmly in Russia.
But a defiant Russian President Vladimir Putin immediately said such attacks would not derail the Kremlin's peace plan for the region. "We can not allow anything like this to happen, nor will we," he told senior officials.
Soldiers guarding the administration building, which also housed the local FSB security services, opened fire on the truck to stop it. But it smashed through concrete security barriers before exploding in a fireball.
The huge blast, near Chechnya's border with Russia and in an area which has long been under Moscow's control, gutted the building and destroyed eight village houses nearby.
Emergency services converged on the area to try to free people trapped beneath fallen masonry and woodwork.
"Forty people have been killed in the blast," a spokesman for Chechnya's Interior Ministry said.
At least 70 people had been taken to hospital with wounds, emergency officials in Moscow said. It was assumed the suicide bombers were killed in the explosion.
Last December, a bomb attack on regional administration headquarters in Grozny killed around 80 people.
GRIM NEWS FOR PUTIN
The blast brought grim news for Putin, who used his tough stance against Chechen rebels to score an easy election victory in 2000, and will cast a shadow over his annual "State of the Nation" address scheduled for Friday.
A low point for Putin came last October when Chechen rebels seized 700 hostages in a Moscow theatre to highlight their separatist cause. A total of 129 people and all the rebels died after Russian forces used a powerful knock-out gas to storm the building and end the siege.
Putin's defiant words on Monday, however, suggested the Kremlin would press ahead with its blueprint to end 10 years of conflict between rebels and Russian forces in the mountainous southern region. The next stage in the peace plan envisages elections in December for regional president.
There was no immediate claim of responsibility from any section of the Chechen armed opposition.
The head of the present pro-Moscow Chechen government, Akhmad Kadyrov, blamed fighters loyal to Aslan Maskhadov, the region's former president, who is now a fugitive and sought by Russian security forces.
"We need to be more vigilant and responsible so that no vehicles with explosives can travel around the territory of the republic," Kadyrov was quoted by Interfax as saying.
"Where did this car with explosives come from? How did it get to Znamenskoye? I have many questions," he said.
(Additional reporting by Richard Balmforth)
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