ROSTOV-ON-DON, Russia (AP)--Rebel attacks in Russia's volatile North Caucasus region killed three police officers and wounded one, officials said Tuesday. 

Two local police officers died late Monday when a homemade bomb disguised as a piece of wood went off near the village of Alleroi in Chechnya's southern mountains, according to the Chechen branch of the Interior Ministry. 

In the neighboring province of Dagestan, unidentified gunmen fired at a police patrol in the town of Khasavyurt near the border with Chechnya, killing one officer and gravely wounding another, authorities said. 

Major fighting in Chechnya, which saw two separatist wars in the past 13 years, ended years ago, but the region and neighboring provinces in Russia's North Caucasus are still plagued by violence, including bombings and guerrilla attacks on police and other officials. 

Some of the attacks have been blamed on Chechnya-based rebels and militant groups in other provinces, while others were rooted in criminal violence.