Two explosions rocked the capital of Russia`s North Caucasus republic of Dagestan early on Monday, no one was injured, a police spokesman reported. "An unidentified explosive device went off in Makhachkala on Magomedtagirova Street near a pizzeria," the spokesman said. "Another explosion resounded on the same street in a few minutes when law enforcers were heading to the site," he said, adding that a police vehicle was damaged. An investigation is underway. Sporadic terrorist attacks and militant clashes are common in Russia`s largely Muslim North Caucasus republics, especially Dagestan, Chechnya and Ingushetia. The Kremlin has pledged to wage "a ruthless fight" against militant groups but also acknowledged a need to tackle unemployment, organized crime, clan rivalry and corruption as causes of the ongoing violence in the region.