|Dagestan has been hit hard by violence after separatists wars ended in neighbouring Chechnya [EPA]
A senior Russian security officer has been killed along with eight anti-government fighters in the province of Dagestan, officials say.
Lieutenant-Colonel Gapal Gadzhiyev, head of the North Caucasus's Federal District's Anti-Extremism police department, was shot dead in his car on Sunday as he was heading to work in Makhachkala, the capital of Dagestan.
Witnesses said in televised remarks that the assassin pulled up in his car with no licence plates next to Gadzhiyev's Toyota near the provincial interior ministry building.
Magomed Tagirov, the interior ministry spokesman, said the eight fighters were killed in a shootout after being surrounded in a house on the outskirts of Makhachkala.
He said they refused to surrender and opened fire at law-enforcement officers.
RIA, a state-controlled news agency, said more than eight fighters may have been killed.
"The special operation is still under way. According to preliminary information, the number of rebels killed could be over eight," RIA quoted a law-enforcement source in Dagestan as saying.
A police spokesman in Moscow declined to comment on the reports when contacted by the Reuters news agency by telephone.
The attack in Makhachkala followed an explosion in the North Ossetia capital of Vladikavkaz, which injured more than 100 people on Thursday.
The Kremlin is still grappling with anti-government fighters aiming to set up an Islamic caliphate in the Caucasus, a decade after federal forces drove separatists from power in Chechnya.
Dagestan, located on the shores of the Caspian Sea, has overtaken its neighbours as the epicentre of violence in the mainly Muslim North Caucasus.
Human-rights groups say poverty, corruption and abusive conduct by government forces in Dagestan stir anger towards the authorities and drive youths into the embrace of armed groups.