Gunmen attacked synagogues and churches in two cities in Russia’s southern republic of Dagestan on Sunday, killing multiple police officers and a priest, in an apparently coordinated assault.

Officials said at least five of the gunmen were killed after shootouts in the two cities, Makhachkala and Derbent, in the predominantly Muslim region of Dagestan on the Caspian Sea. Wielding rifles and Molotov cocktails, they attacked a synagogue and a church in each of the two cities, according to authorities and religious organizations.

Sergei Melikov, Dagestan’s governor, described the attack as the latest assault “on our fraternity, on our multiethnic unity.”

The precise death toll was not immediately clear. Melikov said that “more than 15 police officers fell victim to today’s terrorist attack,” without specifying how many of them were killed and how many were wounded.

The motives and identities of the gunmen were also unclear, and there was no claim of responsibility for the attack. Russia’s Investigative Committee, an analogue to the FBI, said it had begun a terrorism investigation.

Dagestan’s Interior Ministry said a group of armed men shot at a synagogue and a church in the city of Derbent, located on the Caspian Sea. Both the church and the synagogue caught fire, according to state media. They also killed a priest, Nikolai Kotelnikov, according to a spokesperson for the Russian Orthodox Church. The priest was the only confirmed victim of Sunday’s attack who was not a law enforcement officer, although Melikov said “several” civilians had been killed.

At about the same time, early Sunday evening, gunmen also opened fire on a traffic police post in Makhachkala, according to state media reports. The attackers’ targets also included Makhachkala’s Cathedral of the Assumption, according to state media reports, and a synagogue, according to the Russian Jewish Congress.

Videos posted by Dagestan’s interior ministry showed gunmen on the loose in the city of Makhachkala, opening fire and forcing people out of their cars. At one point, police said roads leading out of the city were blocked. It remained unclear late Sunday whether any gunmen remained at large, though Melikov said the “active phase” of the police response was over.

Authorities announced a counter-terrorist operation in the region. The Anti-Terrorist Committee said five gunmen were “eliminated.” The governor said six “bandits” had been “liquidated.” The conflicting numbers couldn’t be immediately reconciled and it wasn’t clear how many militants were involved in the attacks.

Decades of violence

Dagestan is a predominantly Muslim republic that is also home to a Jewish population, and has experienced a heightened level of violence for at least three decades. But ethnic and religious tensions in the republic have worsened since the war between Israel and Hamas in the Gaza Strip broke out in October.

That month, an angry mob stormed an airport in Makhachkala searching for Jewish passengers on a flight from Israel. The episode shocked Jews in Russia and drew condemnation from the Israeli government.

Responsibility unclear

There was no immediate claim of responsibility for the attacks. Russian state news agency Tass cited law enforcement sources as saying that a Dagestani official was detained over his sons’ involvement in the attacks. Some officials in Dagestan blamed Ukraine and NATO.

“There is no doubt that these terrorist attacks are in one way or another connected with the intelligence services of Ukraine and NATO countries,” Dagestan lawmaker Abdulkhakim Gadzhiyev wrote on Telegram.

Ukrainian officials did not comment immediately on the attacks.

This report includes information from the Assocaited Press.