Gunmen in Russia's violence-plagued North Caucasus province of Dagestan shot dead a high-level law enforcement official as well as his daughter, nephew and driver on Friday, authorities said.
The attack happened a day after three bombs exploded in the provincial capital, Makhachkala, killing at least six people and injuring more than 50.
Mostly Muslim Dagestan is beset by near-daily shootings and bomb attacks, many of them blamed on an Islamist insurgency stemming from years of separatist conflict in Chechnya.
The deputy director of the federal prison service for Dagestan, interior ministry officer Magomed Murtuzaliyev, was killed when attackers opened fire on his car on the outskirts of Makhachkala on Friday morning, the interior ministry said.
The other occupants of the car -- Murtuzaliyev's daughter, his nephew and the driver -- were also killed, the ministry said.
Militants in the North Caucasus say they are fighting for a separate Islamic state in the strip of provinces along Russia's southern border. Rights activists say the insurgency is fuelled by poverty and anger at police tactics.