Russian President Vladimir Putin has pledged to root out Chechen separatists, following the suicide bombings at a Moscow rock festival on Saturday which killed 15 people.
Security has been stepped up in the capital
"They must be dug up out of their basements and caves, where
they are still hiding, and destroyed," Russian media quoted Mr Putin as saying.
He added that the methods used indicated that rebel groups were an integral part of international terrorist groups.
The BBC's Nikolay Gorshkov in Moscow says Mr Putin's strong words are reminiscent of a statement in 1999 as prime minister in which he vowed to wipe out rebels "even in the toilet".
Those remarks were occasioned by explosions in apartment blocks in Moscow and elsewhere, which triggered the second Chechen conflict.
Mr Putin's latest statement came amid reports that a helicopter which crashed in Chechnya on Sunday, killing five soldiers, had been shot down.
Interfax news agency quoted sources close to the team investigating the crash as saying that bullet holes had been found in the wreckage.
Earlier reports said the cause was technical failure.
Memorial services were held in Moscow on Sunday to honour those killed in the rock festival blasts - the first suicide attack on the Russian capital.
Recent Chechen attacks
5 June 2003 - 18 people killed in suicide bomb attack on Russian air force bus
14 May 2003 - 16 people killed in suicide bomb attack at religious festival in Chechen town Iliskhan-Yurt
12 May 2003 - 61 people killed in suicide truck bomb attack on government complex in Chechen town of Znamenskoye
27 December 2002 - 80 killed as suicide bombers drive vehicles packed with explosives into government building in Grozny
23-26 October 2002 - 129 hostages and 41 Chechen guerrillas killed in Moscow theatre siege
19 August 2002 - 118 Russian soldiers killed as Chechen rebels shoot down a transport helicopter
More than 50 people were injured in the blasts, several of whom are still fighting for their lives.
The Krylya (Wings) festival in north-western Moscow was packed with about 40,000 people when the bombs went off 15 minutes apart.
Police say the devastation could have been far worse, had vigilant officers not stopped the women at the gate to the concert venue.
Security has been stepped up in Moscow since the attacks, with police checking identification documents and residence permits.
Mr Putin, who on Friday set 5 October as the date for a presidential election in Chechnya, has vowed that he will not be thrown off course by such acts of violence.
However, he has postponed two overseas visits in the wake of the attacks, according to a statement from the Kremlin. Mr Putin had been due to travel to Uzbekistan on Sunday and Malaysia on Tuesday.
The main separatist movement, led by Aslan Maskhadov, has said it played no part in the attacks, but correspondents say the separatists are deeply split and only a few are believed to follow Mr Maskhadov's orders.
Our correspondent says some Russian politicians believe unless the Kremlin prosecutes those responsible for human rights abuses in Chechnya and starts talks with the rebels, Moscow and other Russian cities will never be safe.
No-one has yet claimed responsibility for the blasts, but interior ministry officials say they have established clear links to Chechen rebels.
Police said a Chechen passport was found on one of the bombers and the explosive devices are reported to be of the same type used in previous attacks in Chechnya.
Whoever is responsible, the blasts seem likely to increase a sense of vulnerability among Moscow residents.
There have been heightened fears of attacks since last October when Chechen militants took hundreds of people hostages at a theatre.
That resulted in the deaths of 129 hostages and 41 rebels, including women armed with explosive belts, after Russian special forces pumped noxious gas into the building to end the siege.