Russian security forces went on high alert after six bodies and several explosive devices were discovered on the outskirts of Pyatigorsk near the Caucasus mountains 500 kilometres from Sochi.
The gunshot riddled bodies were found in four abandoned cars spread out across two districts near the regional capital Stavropol.
A homemade explosive device detonated near one of the cars. Three other explosive devices were found with the vehicles but none was triggered.
Russian state news is reporting that three of the men killed have been identified as two taxi drivers and a furniture assembly worker. The names have not been released but they are all local residents who drove Soviet era Lada cars.
The other three have not yet been identified and were all found in one vehicle. The investigation will continue with the Russian Federal Security Service joining local police efforts.
Police have not indicated a potential motive or whether this was a criminal act or an act of terrorism.
This latest incident comes after a suicide bomb attack in Volgograd train station and a second attack on a trolleybus in December prompted higher security across the country. Concerns over security for the upcoming winter Olympics in Sochi have led Russia to strengthen its efforts.
The region borders the Caucasus mountain range where an Islamic insurgency has promised to disrupt the Olympics with terrorist attacks. NTV reports that border security at a nearby crossing into the predominately Muslim Russian republic of Kabardino-Balkaria were heightened soon after the attacks.