A chief organiser of twin suicide bombings that left 40 people dead in Moscow's metro in March was killed by security forces on Saturday, a federal law enforcement agency said.
The body of Magomed-Ali Vagabov was found in the wreckage of a home that was stormed by security forces in the Dagestan province in the North Caucasus, a representative of Russia's National Anti-Terrorism Committee said.
The official said Vagabov was a mastermind of the March 29 morning rush-hour bombings in Moscow. He was also an insurgent leader who was active in recruiting young people to join militants and training suicide bombers, he said.
The mostly Muslim North Caucasus, on Russia's southern flank, is plagued by an Islamic insurgency stemming from separatist wars that devastated one of its republics, Chechnya, in the 1990s.
There has been an increase in violence linked to the insurgency in the past two years in Chechnya and neighbouring Dagestan and Ingushetia.
A total of five suspected militants were killed in the fighting on Saturday in the Dagestani village of Gunib, authorities said.
Russian media have reported that Vagabov was married to one of the female suicide bombers authorities said carried out the metro attacks -- the deadliest in Moscow in six years.