Six police officers and a priest were killed and 12 others injured in shootings at two orthodox churches, a synagogue and a traffic police post on Sunday in southern Russia's Republic of Dagestan, local media reported.

The shootings occurred in the coastal city of Derbent and the Dagestan's capital city of Makhachkala, according to media reports.

The Russian Investigative Committee has initiated criminal cases under the article related with terrorist attacks on the shootings and a counter-terrorist operation regime was introduced in Dagestan, according to the National Anti-Terrorism Committee.

Two of the attackers involved in the shootings have been shot dead, according to TASS, citing the republic's ministry of internal affairs.