Gunmen fired automatic weapons at a Mercedes carrying Arip Aliyev, police chief in Daghestan's Buinaksk District, in Makhachkala at about 11:00 p.m. local time (7:00 p.m. GMT). Aliyev, who suffered head and chest injuries, died at the scene, a ministry spokesman said.
Police are currently searching for the attackers.
Daghestan, which neighbors Chechnya, frequently experiences militant violence and contract killings related to organized crime.
A police officer was killed and a civilian wounded last Thursday, when unknown assailants attacked a police checkpoint in the republic.
In Chechnya's capital, Grozny, police said on Tuesday they had prevented a terrorist act. A powerful homemade explosive device was found in an open-air cafe on Monday. The device was hidden in a saucepan and was to be activated by cell phone, a police source said.