Russian President Vladimir Putin has ordered the southern city of Nalchik sealed off following fighting between gunmen and security forces that left more than 60 people dead.
Deputy Interior Minister Alexander Chekalin says Mr. Putin also instructed security forces to shoot to death anyone resisting them.
Russia's Itar-Tass news agency says the dead include 50 gunmen and some 12 local residents of Nalchik, the capital of Russia's Kabardino-Balkaria Republic.
The Kremlin's envoy to the region Dmitry Kozak says gunmen have also taken hostages in a police station. He did not provide details.
Officials say the gunmen launched simultaneous attacks on several government buildings, the police headquarters and the airport.
Chechen separatists claimed responsibility for the attacks in a message posted on a website linked to the militants.
Kabardino-Balkaria borders Chechnya, where Russian government troops have been battling separatist forces for most of the past decade.