Gunmen opened fire on police in the capital of a troubled Russian region early Wednesday, killing one officer before fleeing, law enforcement officials said, according to AP. Police in Dagestan, which borders Chechnya to the east, had stopped an armored car driven by two or three gunmen around 4 a.m. (1200GMT) in Makhachkala when the shooting broke out, Dagestani Interior Ministry officials said. Police later found explosives in the recovered car. Dagestan has seen a steady series of attacks on police and other officials, some of which were tied to the conflict in Chechnya while others are rooted in turf battles over fishing and other lucrative economic activities, infighting between local criminal clans and public anger over police brutality. Dagestani police clashed with gunmen on the border with Chechnya overnight, killing two and wounding one, a federal Interior Ministry spokesman said. On Wednesday, Dagestan's Supreme Court sentenced a local resident to 17 years in prison on charges of involvement in the killings of two police officers in 2004 and 2005, said court spokesman German Kostrov. In Chechnya, Interior Ministry officials said Wednesday that police troops had clashed with militants in a southwest district, killing two. And in a southeast district of Chechnya, Defense Ministry troops killed two other militants after discovering a hidden camp.