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MOSCOW, March 18 (Reuters) - A website sympathetic to Islamist militants fighting Russian rule in the North Caucasus said on Tuesday the insurgency's leader, Doku Umarov, had been killed.
The death of Russia's most wanted man, who called for attacks on last month's Winter Olympics in Sochi, has been reported before by the Kremlin-backed leader of the Chechnya region but not by Umarov's sympathisers.
A spokesman for Russia's National Anti-Terrorism Committee was quoted by state news agency RIA as saying he could not confirm Umarov was dead.
The Kavkaz Centre website did not say when or how Umarov had been killed. It called him a martyr who had "given 20 years of his life to the Jihad."
Umarov has defied Russian security forces for years as the head of the insurgency seeking to carve an Emirate out of Russia's mostly Muslim southern Caucasus provinces.
His death would be a breakthrough for President Vladimir Putin in the fight against the militants. (Reporting by Alissa de Carbonnel; Editing by Steve Gutterman/Timothy Heritage)