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, RIA Novosti reported.
"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.