Russian media are reporting that a gunman opened fire with a hunting rifle on churchgoers leaving a service in the Dagestan region, killing four people and wounding four others. Police then killed the assailant.
The shooting took place Sunday evening in Kizlyar, a town of about 50,000 people on the border with Chechnya.
State news agency Tass cited Mayor Alexander Shuvalov as saying four people were killed and four wounded.
The motive for the shooting was not immediately known.
Dagestan is a predominantly Muslim region between Chechnya and the Caspian Sea. Following two separatist wars in neighboring Chechnya, an Islamist insurgency spread to Dagestan.