GROZNY, Russia - Moscow's most wanted Islamist militant Doku Umarov warned that Russia would be the target of a newly strengthened insurgency in a video posted on an Islamist affiliated website on Monday.

A decade after Russian forces drove a separatist government from Chechnya, Moscow is struggling to contain an insurgency that wants an Islamic state in Russia's North Caucasus.

Chechen-born Umarov, 47, claimed responsibility for masterminding the January suicide bombing of Moscow's Domodedovo airport, which killed 37. He has also promised a year of "blood and tears" for Russia ahead of parliamentary elections in December and a presidential poll in 2012.

Security will be a top priority leading up to the polls for both President Dmitry Medvedev and Prime Minister Vladimir Putin, who led the country into a second devastating war against Chechen rebels in 1999.

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