Bomb kills three, wounds five in Russia's North Caucasus MAKHACHKALA, Russia (Reuters) - An improvised bomb killed two policemen and one civilian in Russia's volatile North Caucasus on Wednesday and wounded five others, police said. The bomb went off in Dagestan, an internal mostly Muslim republic, which has been beset by violence blamed on insurgents seeking to create an Islamic state in the North Caucasus, more than a decade after Russian troops ousted a separatist government in neighboring Chechnya. The deadly explosion took place when police entered an empty former bank building in the town of Shamilkala to inspect an area near the site of an earlier bomb blast that had caused no casualties, the regional Interior Ministry said. Insurgents in the Caucasus, on Russia's southern border, have frequently killed policemen by luring them to a site with an initial blast and then setting off a second explosion. President Vladimir Putin last month told security forces to ensure there are no attacks on any of the major events that Russia is to host in the coming years, including the 2014 Winter Olympics in Sochi, near the North Caucasus. Writing by Nastassia Astrasheuskaya; Editing by Andrew Osborn