Federal Security Service officers killed 10 militants in Dagestan, regional authorities said on Wednesday.
The commandos ambushed a Gazel minivan carrying insurgents, along with weapons and explosives on a road near the Russian border with Azerbaijan, the Dagestani branch of the FSB in a statement.
The FSB commandos fired several rocket-propelled grenades in the minibus and the rebels sprayed with gunfire from automatic firearms, said the statement.
Two FSB officers were wounded in the fighting, one of whom died later in hospital.
Wednesday bite of the operation came after two recent campaigns by the security services on the same network Islamist rebel, who was active in the south of Dagestan, local security officials said.
Three policemen were killed in a clash on September 7, like that five militants, including Ilgar Mollachiyev, whom the rebels Chechen leadership has appointed last fall as commander of the Dagestani insurgents. The next day, three policemen were killed in a skirmish with members of the group Mollachiyev law enforcement who tried to encircle near the village of Sirtych.
Dozens of officials responsible for enforcing the law are killed each year in Dagestan, where ethnic rivalries and Islamist separatism - exacerbated by police brutality and official corruption - prompt young men to join violent anti-government groups.
Dagestan president Mukhu Aliyev has repeatedly demanded - in vain - that the police desist from brutal attacks on local residents. A campaign is under way in the Republic to expel Dagestani Interior Minister Adilgirei Magomedtagirov, the answers to the federal government.
Sergei Markedonov, a Caucasus expert at the Institute of Political and Military Analysis, said that due to widespread corruption and nepotism, rooted in Dagestan and Ingushetia, the deadly violence has become the only form of political protest from disgruntled with the status quo.
"Moreover, recent events in Dagestan demonstrate that the Kremlin's claims to have crushed the insurgency networks in the Caucasus are not true," he said.