Gunmen opened fire at a synagogue, an Orthodox church and a police post in Russia's North Caucasus region of Dagestan on Sunday, killing six policemen and injuring 12, the region's Russian news agencies quoted the interior ministry as saying.
A local religious organisation in the mainly Muslim region put the death toll at nine, including seven police officers.
The Interior ministry, quoted by Russian news agencies, said four gunmen had been shot dead as the incidents unfolded. A local official said another had been killed during a shootout at a church in Makhachkala, the region's main administrative centre.
An Orthodox priest was also reported to have been killed.
Restive Dagestan was in the 2000s hit by an Islamist insurgency spilling over from neighbouring Chechnya, with Russian security forces moving aggressively to combat extremists in the region.
The agencies reported exchanges of gunfire in the centre of Makhachkala, a region with a long coastline on the Caspian Sea.
An unofficial channel on the Telegram messaging app, Mash, said police were preparing to storm a building where gunmen were holed up in Derbent, about 125 kilometres (75 miles) further south.
The gunmen attacked a synagogue and a church in Derbent, home to an ancient Jewish community and a UNESCO World Heritage site. The Interior Ministry was quoted as saying that both the synagogue and church were ablaze.
The head of Dagestan's regional government vowed stiff punishment for "whichever forces lies behind these disgusting actions".
In Israel, the Foreign Ministry said the synagogue in Derbent had been burned to the ground and shots had been fired at a second synagogue in Makhachkala. The statement said it was believed there were no worshippers in the synagogue at the time.
Russian authorities have pointed to militant Muslim elements in previous incidents in the region.
Last October, after the war in Gaza broke out, rioters waving Palestinian flags broke down glass doors and rampaged through Makhachkala airport to look for Jewish passengers on a flight arriving from Tel Aviv.
Russian President Vladimir Putin accused the West and Ukraine of stirring up unrest inside Russia in connection with the incident.
