Russian special forces killed five gunmen on Sunday, including an Arab rebel leader, in the southern republic of Dagestan which borders Chechnya, a Russian intelligence agent said.
Russia has fought two separatist wars in Muslim Chechnya since 1994 with heavy loss of life. The wars have spilled over into neighbouring Dagestan and Ingushetia, which have witnessed an upsurge in violence over the last few years.
Special forces surrounded a house in Khasavyurt in the west of Dagestan in an early morning raid and killed three gunmen in an initial exchange of shooting.
"The others were offered a chance to surrender," said Mikhail Merkulov the deputy head of Dagestan's FSB, Russia's intelligence service.
"After receiving a negative reply the FSB soldiers broke into the house and shot two more gunmen. One of them was foreign terrorist-mercenary Abu Havs".
Chechnya's Prime Minister and leader of its most powerful pro-Kremlin militia group, Ramzan Kadyrov, said Abu Havs's death would help bring stability to the region.
"I believe that the liquidation of Abu Havs will be a positive influence on the situation not only in Chechnya but also in the whole region. In the last year he has been spending a lot of money on funding terrorist acts," Kadyrov told Interfax news agency.