"The warriors of the Khalifate were able to attack a group of Russian special service officers in the city of Derbent in southern Dagestan, killing one officer and injuring the others," the terrorist monitoring organization SITE quoted ISIL as saying on Wednesday, AFP reported.
The deadly attack took place on Tuesday night near the citadel of Derbent, which claims to be Russia's oldest city, and which this year celebrated its 2,000th anniversary.
The shooting took place as Russian warplanes wrapped up two days of intensive bombing raids over Syria, carrying out 121 sorties in which they hit 424 targets, the military announced on Wednesday.
The shooting targeted Russian security forces, with an unnamed source telling RIA Novosti state news agency that a member of the Federal Security Service (FSB) had been killed and another injured in the shooting.
The gunmen, who were reportedly in the forest, opened fire at people standing by the fortress, which was declared a UNESCO World Heritage site in 2003.
Sixty-seven bullet casings were recovered at the scene, a law enforcement source told Interfax news agency on Wednesday.