Up to 500 Chechen guerrillas have broken out of Grozny and reached the village of Alkan Khala, forcing their way through Russia's "ring of steel" surrounding the Chechen capital.
In the course of the action a number of leading rebel commanders were killed when they drove into a minefield and were subjected to a Russian artillery bombardment. Mr Shamil Basayev, the region's most feared warlord, was reported to have had a leg blown off when his car struck a mine.
While Russian forces can claim greater success in their push towards the centre of Grozny, the Chechen breakthrough is a major embarrassment for them as they had claimed to have sealed off all avenues open to Chechens who wished to beat a tactical retreat.
The breakthrough came at a time when the acting President, Mr Vladimir Putin, was seen, for the first time in the conflict, to be losing support among the Russian public.
The most recent poll shows his support to have fallen below the 50 per cent necessary to avoid a second round of voting in the forthcoming elections. A shift to guerrilla warfare by Chechen insurgents could further damage his popularity.
A rebel spokesman, Mr Movladi Udugov, announced yesterday that all the rebels in the city had broken through the Russian cordon and were regrouping in the countryside.
The Kremlin's chief spokesman on Chechnya, Mr Sergei Yastrzhembsky, denied any breakthrough had taken place and said that fierce fighting continued in Grozny.
The truth probably lies somewhere between the claim of Mr Udugov and the statement from Mr Yastrzhembsky.
There appears to be little doubt that a large number of rebels have escaped from Grozny, where Mr Putin had promised to eliminate them. There also appeared to be considerable numbers of rebel snipers still in the city and although the progress of Russian forces towards the centre had speeded up they were still meeting strong resistance.
Yesterday's move was typical of Chechen tactics from the 1994-1996 Chechen war.
In that conflict Russian forces captured Grozny in 1995 from rebels who fled to the countryside to conduct a protracted guerrilla campaign. In 1996 a rebel force launched a surprise attack on Grozny and recaptured the city, bringing the war to an end.
While western news agency reports from the region said that Mr Basayev had lost a leg in the rebel breakthrough the Chechen news agency Kavkaz-Tsentr quoted him as saying his forces would "continue their struggle according to the plans for the defence of the Chechen Republic of Ichkeria".
Chechen sources confirmed that Gen. Aslambek Ismailov and Gen. Khunkarpasha Israpilov were killed in action yesterday and that the mayor of Grozny, Mr Lecha Dudayev, a nephew of Chechnya's independence leader, Mr Dzhokhar Dudayev, had lost his life in Grozny on Sunday night.
