Attacks on police officers, churches and synagogues in Russia’s North Caucasus republic of Dagestan have left many people dead.Gunmen targeted the cities of Derbent and Makhachkala on the Orthodox festival of Pentecost.The dead include at least 15 police officers, a priest and a security guard. Six of the attackers are dead and police are hunting for others.The assailants have not been identified, but Dagestan has in the past been the scene of Islamist attacks.Two churches and two synagogues were targeted in Sunday’s attacks. An Orthodox Church priest was killed in Makhachkala, Dagestan’s…