Police killed three militants Thursday after an hours-long siege at an apartment in a southern Russia region in the latest sign of persistent violence in areas surrounding conflict-torn Chechnya, AP reported. A criminal gang leader was among those killed, said Col. Gen. Arkady Yedelev, a top counter-terrorist official for Russia's North Caucasus. No police were injured in the gunfight, which began Wednesday evening in Makhachkala, capital of the province of Dagestan, as the rebels exchanged gunfire from an upper story window with security forces on the ground, authorities said. Russian television showed footage of gunfire coming from a window near the top of the 11-story building and armored vehicles on the street below. Initially, authorities had estimated that about five rebels were involved, but there was no indication that any of the rebels escaped. Dagestan frequently has been hit by attacks targeting police and government officials. The violence is blamed on gang and business disputes as well as fighting spilling over from neighboring Chechnya, which has been wracked by a separatist insurgency for the past decade.