Khura-Magomed Ramazanov, a deputy chief mufti at the central mosque in the provincial capital, Makhachkala, died when a radio-controlled roadside bomb turned his vehicle into a fireball, regional emergency agency spokesman Sergei Petrov said.
Ramazanov's driver was also killed in the attack, but his bodyguard survived it with grave injuries and was hospitalized.
Police in Dagestan confirmed that a top cleric and his assistant died when their car burst into flames, but would not immediately give any further details.
Dagestan, a mostly Muslim region east of Chechnya that is home to many ethnic groups, has been plagued by shootings, bombings and other violence, including regular attacks on top officials and police. Some of the violence was linked to Islamic extremists with links to Chechen rebels and some was rooted in turf battles between local criminal clans.
The face of USA's First Lady Melania Trump after her handshake with Russian President Putin has received a lot of attention in social media
Moscow is trying to stop Balkan countries from entering NATO. Greece eventually took measures against Russia, even though Greek Prime Minister Alexis Tsipras had earlier said that Russia was Greece's strategic partner
The Ukrainian government refuses to abode by its obligations, rejects a peaceful resolution of the conflict, and disregards its own people, the president said