Shots have been fired at a synagogue and two Orthodox churches in the Russian republic of Dagestan, reports AFP.
Several people are reported to have died, including a priest and several police officers.
Four perpetrators are reported to have been killed by the police.
"This evening, armed attacks were carried out on two Orthodox churches, a synagogue, and a police outpost in the cities of Derbent and Makhachkala", reads a statement from Russia's anti-terrorism agency.
In total, eight people are said to have been killed, including six police officers. A further twelve people have been injured, according to Dagestan's interior minister, as reported by the Russian state news agency Ria Novosti. A 66-year-old priest is said to have been killed in Derbent.
According to the department, the police have killed four perpetrators.
No one has claimed responsibility for the attacks, but high-ranking local politicians are accusing both the defence alliance NATO and Ukraine of involvement, according to the news agency AP.
"There is no doubt that these terrorist attacks are in some way connected to the intelligence services of Ukraine and NATO countries", writes a representative of the republic's government on Telegram.
The synagogue in Derbent is also on fire after the attack, according to a Jewish representative.
"Unknown attackers attempted this evening to destabilise the situation in society in Derbent and Makhachkala", writes the republic's governor, Sergei Melikov, on Telegram.
The coastal cities of Derbent and Makhachkala, the republic's capital, are approximately twelve miles apart.
