The gunmen opened fire from a Lada car after police had stopped the vehicle.
"The militants were killed as the police returned fire," the source said.
No police officers were injured in the shootout. Two Kalashnikov assault rifles, a Makarov pistol, and a hand grenade were found in the car.
Russia's volatile North Caucasus region has seen a surge in militant attacks against police and civilians in recent months.
In a separate development, an explosive device containing 5.5 kg of TNT and filled with nuts and bolts to increase its destructive power was found in the village of Neitrino in the republic's Elbrus Region.
Add to blog
You may place this material on your blog by copying the link.
Image Galleries: Albino Kangaroos, Grubby Baby Penguins and Other Animal News
Infographics: History of the Paralympic Games
We have witnessed the total defeat of western Ukraine, Western nationalists and the West in general, which made the unfortunate decision to support the anti-government activity. They failed to realize that the collapse of Yanukovych means the collapse of Ukrainian unity. They set fire to their own home and planted a time bomb under Ukraine’s territorial integrity.