Chechen rebels have claimed responsibility on a website for an attack on the main city of the Russian republic of Kabardino Balkaria which caused heavy casualties.
Russian forces are said to have killed around a third of the 150 gunmen who targeted government buildings in Nalchik.
Twelve civilians are also said to have been killed.
Kabardino-Balkaria is near the North Ossetia province where Chechen militants attacked a school in Beslan last year, resulting in the deaths of 331 people, half of them children.
Doubts have been cast on earlier reports that the attackers had entered a school close to a police station, sparking fears that children may have been taken hostage.
The attack on Nalchik is reminiscent of an operation in June 2004 when pro-Chechen militants attacked police buildings in Nazran and effectively seized control of Ingushetia. About 60 people, many of them police, were killed in that attack.
A regional security source has been quoted as saying the attacks have now been repelled and that a hunt is underway to track down the rest of the armed gang.