In a series of coordinated attacks, unknown gunmen targeted a synagogue, two Orthodox churches, and a police post in Russia's North Caucasus region of Dagestan on Sunday, leaving at least 15 policemen and a priest dead.

"This evening, armed attacks were carried out against two Orthodox churches, a synagogue and a traffic police post in the cities of Derbent and Makhachkala. As a result of the terrorist attacks, according to preliminary information, a priest of a Russian Orthodox Church and police officers were killed. Law enforcement agencies are taking all necessary measures to search for and apprehend the criminals," Russia's National Anti-Terrorism Committee told Sputnik news agency.

Later in the day, the chair of the Federation of Jewish Communities of Russia's Public Council, Boruch Gorin, told Sputnik that another synagogue, located in Makhachkala, had also been set on fire by the attackers.

The identities of the attackers were not known.

The priest, who was killed in the attack, was identified by Dagestan Public Monitoring Commission Chairman Shamil Khadulaev as Father Nikolay.

“They slit his throat. He was 66 years old and very ill,” Khadulaev told CNN.

No group has claimed responsibility for the attacks so far.

This incident occurred just months after ISIS terrorists took responsibility for the attack on Crocus City Hall in Moscow which left 140 people dead.

It was one of the worst terror attacks registered by the country in recent years.

Dagestan is predominantly a Muslim region which also houses a small number of Christians and Jews.