Security forces in Russia's North Caucasus province of Daghestan were searching for armed militants after police found the bodies of five people with gunshot wounds in a car in the capital, Makhachkala.
Police said the victims were local residents and may have been killed by militants.
They launched a "counterterrorist" operation in the city's Kirov district, where police on September 2 killed a man they later identified as a wanted militant, Rajab Mustafayev.
Islamist militants in Daghestan and other mostly Muslim provinces of the North Caucasus, including neighboring Chechnya, are waging an insurgency that stems from two post-Soviet separatist wars between Chechen rebels and government forces.
Daghestan is also plagued by violence linked to organized crime.
Based on reporting by ITAR-TASS, Interfax, and RIA Novosti