MOSCOW (Reuters) -- Police have killed four rebels in heavy fighting in Russia's Daghestan region and a suicide bomber wounded three policemen in neighboring Chechnya as militants pressed a campaign against Kremlin rule.
One day earlier, on September 11, a suicide bomber blew himself up in the third region currently suffering insurrection -- Ingushetia -- killing one and wounding at least five.
A series of suicide bombings and armed attacks on security forces in the mainly Muslim regions of Chechnya, where Russia has fought two separatist wars, Ingushetia and Daghestan have shattered a few years of relative calm in the North Caucasus.
Russian security forces say they have completed a military operation in Daghestan's main city of Makhachkala, killing four people suspected of complicity in the murder of senior member of the local prosecutor-general's office, Interfax news agency reported.
In Chechnya's capital, Grozny, a suicide bomber blew himself up when police tried to arrest him, Interfax said. Two of three policemen wounded were in grave condition.
Growing turbulence in the North Caucasus has become a major headache for the Kremlin, which is worried violence could spill over into other parts of Russia -- a vast country spanning 11 time zones, which is home to some 20 million Muslims and dozens of nationalities.