Shamil Basayev, a Chechen warlord who claimed responsibility for the deadly school hostage-taking in southern Russia, released a video statement to dispel rumours about his death.
He also pledged respect for a rebel truce that federal officials have dismissed as propaganda.
The statement that appeared on a Website linked to the rebels, www.kavkazcenter.com, featured Basayev, clad in combat fatigues and ski cap, saying he was feeling strong.
He then stabbed a knife into his artificial leg twice saying: "My leg is also in good shape try to do it if you can."
Basayev lost his right leg below the knee when he stepped on a Russian mine in 2000.
Basayev's statement, which the rebel Website said had been recorded in Chechnya on Sunday, followed a stream of recent Russian media reports claiming Basayev had been killed.
Speaking against a backdrop of black cloth with white letters in Arabic, Basayev said he was respecting a ceasefire announced by former Chechen President Aslan Maskhadov.
