Four militants were killed in a special operation in Russia's volatile southern region of Dagestan, the local branch of the Federal Security Service (FSB) said on Saturday.

The security forces gunned down four militants who put up armed resistance in the clash in the village of Zubutli-Miatli, Russian news agencies quoted a local FSB official as saying.

Three of the dead have been identified as members of a local terrorist group, the official said.

Russia's troubled North Caucasus republics, particularly Chechnya, Dagestan and Ingushetia, have been plagued by violence stemming from Islamist militants and criminal groups.

Russian President Dmitry Medvedev highlighted security and economic problems in the mainly Muslim region late last year and ordered measures to end militant violence, clan rivalries, and pervasive corruption there.