Police said Deputy Interior Minister Magomed Gazimagomedov was not in the vehicle when the attack took place in Makhachkala, Daghestan's capital.
In a separate incident earlier today in Daghestan, the Interior Ministry said a shootout erupted between police and a group they were trying to apprehend.
The ministry said three officers were injured in the fighting in the village of Nuradilovo near the Chechen border. AFP reported that a police officer and a gunman were also killed.
Daghestan is frequently the scene of violent attacks aimed directly at Russian law enforcement personnel and facilities.
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