Moscow [Russia], Authorities in the Russian region of Dagestan have identified people with notable backgrounds, including a former mixed martial arts (MMA) fighter and relatives of a regional official, among the attackers involved in Sunday's attacks on locations cult in which at least 20 people were killed. lives, the Russian state news agency reported.

Five attackers responsible for the violence in Derbent and Makhachkala have been identified, TASS reported citing police sources on Monday.

The gunmen attacked multiple places of worship and clashed at a police traffic stop in these cities within the Muslim-majority republic. The attacks left at least 15 police officers and four civilians dead, including an Orthodox priest.

Some of the attackers came from the Sergokalinsky district, located between Derbent and Makhachkala, and were linked to the head of the district. Former MMA fighter Gadzhimurad Kagirov, identified as a cousin of district head Magomed Omarov, was among those involved in the violence in Derbent, TASS reported.

Additionally, Omarov's relatives, including his son and his nephew, were reported to have participated in the attacks, according to TASS.

Sergei Melikov, head of Dagestan, addressed the media on Monday and confirmed Omarov's removal from office and his expulsion from the United Russia party, one of Russia's most prominent political entities.

Although Melikov refrained from specifying the exact involvement of Omarov's relatives in the attacks, he emphasized that the investigating authorities would determine his guilt. He stressed that if Omarov's direct involvement is proven, corresponding legal consequences will follow.

Melikov further stressed that, regardless of his direct involvement, Omarov is responsible as a father for the actions of his children, and questioned why potential warning signs were overlooked, given his position and responsibilities within the municipality and the political party.

"Why is he, as the head of a municipality, as a member of the United Russia party, as a high-level leader, who has been serving for several years as the head of a municipality, whose duties are to take care of the entire population of the region , they didn't pay attention, they missed the children [the children's actions and possible warning signs], and they missed them so much that they became murderers," he said, TASS reported.

The death toll from attacks by gunmen on a synagogue and church in Dagestan, Russia, has risen to 20.

Three days of mourning followed in the Dagestan region of Russia's North Caucasus.

At least 15 police officers were killed along with several civilians, including an Orthodox priest. It was also reported that five attackers had been "liquidated." At least 12 people were also injured in the attacks.

The Russian Orthodox Church said its archpriest Nikolai Kotelnikov was also "brutally murdered" in Derbent, Al Jazeera reported, citing Russia's Investigative Committee.

Gunmen attacked churches, synagogues and police posts in the cities of Derbent and Makhachkala on Sunday, the Pentecost holiday of the Russian Orthodox Church. The locations were also reportedly attacked.

Videos posted on social media and shown on Russian television showed the skies over Derbent, home to an ancient Jewish community in the largely Muslim region, filled with smoke and flames after the synagogue was set on fire, Al Jazeera reported.

The Investigative Committee said it had opened criminal investigations into "acts of terrorism" in Dagestan, Chechnya's neighbor and one of Russia's poorest parts of the country.

Dagestan authorities announced on Monday the start of three days of mourning.