A ``cordon sanitaire' has been erected around the Chechen border stretching along Dagestan. The block became operational since Tuesday night, the Russian defence department announced on Tuesday.

``The whole area has been cordoned off so that not a living soul will be able to carry out subversive attempts,'' General Alexander Agafanov, the defence department spokesman, said even as he admitted that the situation along the borders remained ``very complicated and dangerous''.

The formal announcement of the sealing off came on Wednesday. Rianovosti quoted Alexei Kulakovsky, envoy in North Ossetia and Ingushetia on the edge of Chechnya, as saying that the border had been closed late Tuesday and no traffic would be allowed to cross it from Chechnya.

Reports about dreaded terrorist Osama Bin Laden's decision to finance training ``death squads'' to carry out crimes in theheartland of Russia has alarmed the security services all over the country.

Russian Premier Vladmir Putin, appearing on Russian TV, disclosed his government's decision to carry out air strikes on all the bases of Shamil Basayev. This will be the third time this week that Moscow would resort to this operation in the so far impregnable wall around Chechnya, being ruled my rebel Muslim fighters.

Russian armed forces have completed the first round against terrorists on Dagestan-Chechen borders. A second round, if necessary, would commence with ground operation inside the ``rogue'' republic of Chechnya, General Valery Manilov, a senior commander coordinating operations in North Caucasia told Voice of Russia.

Fresh reports from the disturbed areas in North Caucasus speak about direct hits being made by the Russian air force on the headquarter of Chechen rebel leader Shamil Basayev. ``Airstrikes on it has been quite successful,'' Novosti claimed.