MAKHACHKALA , Russia — Police in the restive province of Dagestan in southern Russia say masked gunmen have shot and killed a Muslim cleric. Vyacheslav Gasanov, a spokesman for the local branch of Russia's Interior Ministry, said two unidentified assailants shot and killed Khadzhi Aliyev at his house late Sunday. Aliyev was the imam at a mosque in the village of Khadzhalmakhi. Dagestan has become the epicenter of an Islamic insurgency that has spread across the region after two separatist wars in Chechnya. Shootings, bombings and police security raids occur on a daily basis in the Caspian Sea region, which borders Chechnya to the east. The North Caucasus province has seen a string of attacks on moderate Muslim clerics who have publicly denounced the spread of radical Islamic groups. — AP