Attacks on police officers, churches and synagogues in Russia’s North Caucasus republic of Dagestan have left many people dead.
Gunmen targeted the cities of Derbent and Makhachkala on the Orthodox festival of Pentecost.
The dead include more than 15 police officers and several civilians. Six of the attackers are dead.
Two churches and two synagogues were targeted in Sunday’s attacks. An Orthodox Church priest was killed in Makhachkala, Dagestan’s largest city.
The figure of more than 15 police officers killed was given by Dagestan’s republican leader Sergei Melikov. He also said several civilians had lost their life, including a priest, Father Nikolai, who he said had served in Derbent for more than 40 years.
Mr Melikov announced that three days of mourning would begin on Monday.
The attackers have not yet been identified, but in a video on Telegram, Mr Melnikov said: “We understand who is behind the organisation of the terrorist attacks and what goal they pursued,” without elaborating further.
Footage posted on social media shows people wearing dark clothes shooting at police cars, before a convoy of emergency service vehicles arrive at the scene.
In Derbent – home to an ancient Jewish community – gunmen attacked a synagogue and a church, which were then set on fire.
A police vehicle was also reportedly attacked in the village of Sergokal. Police detained Magomed Omarov, head of the Sergokalinsky district near Makhachkala, following reports that two of his sons were among those who carried out Sunday’s attacks.
Dagestan will hold three days of mourning.
Russian news agencies reported on Monday morning that the counter-terrorism operation launched after the attacks had now come to an end.