A leading Chechen rebel on Wednesday called on Islamist militants in Russia's North Caucasus to disrupt the upcoming Olympics in the Black Sea resort of Sochi, reversing his previous appeal not to target civilians in the region.
Sochi is hosting the Winter Games in February, a pet project for President Vladimir Putin, who is determined for them to be a success.
The overall bill for the games stands at $51 billion, making them by far the most expensive Olympics in history.
Doku Umarov, a widely known Chechen rebel leader, urged his fighters to "do their utmost to derail" the games, which he described as "satanic dances on the bones of our ancestors."
"We have the obligation to use all means to prevent this," he said in a video posted on a rebel website on Wednesday.
Umarov last year urged his fighters to avoid hitting civilian targets because Russians in Moscow were taking to the streets en masse to protest against Putin.
Security experts have said the Islamic insurgency raging across the North Caucasus mountains that tower over Sochi is a daunting threat to the games — although rebels have not attacked Sochi so far. Dagestan, about 500km east of Sochi, has become the center of the insurgency that spread across North Caucasus.