Russian special forces have killed eight militants, including two regional commanders of insurgent groups, in the country's turbulent North Caucasus region, officials said on Saturday.
More than a decade after federal forces drove separatists from power in a war in Chechnya, Russia is still struggling to contain an Islamic insurgency across the mainly Muslim Caucasus region.
Islamist insurgents claimed responsibility for a suicide bombing at Moscow's Domodedovo airport that killed 37 people in January 2011 and twin bombings that killed 40 people in the Moscow metro in 2010.
Security forces launched two operations late on Friday, Russia's National Anti-Terrorism Committee (NAK) said.
The two commanders killed, Islam Magomedov, 28, and Arsen Magomedov, 29, have been on the special forces' wanted list since 2010, an NAK spokesman in Moscow told Reuters.
They were responsible for several attacks, including bombings, against civilians and law-enforcement officers, the spokesman said.
"Seven militants, including two local leaders, have been eliminated in a fire exchange in the Kayakent and Sergokala districts of Dagestan," the spokesman said.
The eighth militant was killed during an operation in the Kabardino-Balkaria region, he said.
Militants in the North Caucasus say they are fighting for a separate Islamic state in the strip of provinces along Russia's southern border.
In May, Russian authorities said they foiled a plot to attack the 2014 Winter Olympics in the Black Sea resort of Sochi, a region the militants consider part of their historical homeland.