ISIS claimed responsibility for an attack on a church in Muslim-majority Dagestan, southern Russia, on Sunday.

Five people died when a gunman, later identified as 22-year-old local resident Khalil Khalilov, opened fire on Orthodox worshippers leaving mass in Kizlyar, a town in the Russian North Caucasus region.

ISIS' Russian affiliate claimed the attack via the militants' news agency Amaq. It said: 'Putting his trust in Allah, one of the zealous soldiers of Islam, Khalil ad-Dagestani (may Allah accept him) set out towards the Christian temple of George in Kizlyar city in Dagestan. He targeted the Crusaders with his rifle, killing 5 of them and wounding 4 others, and to Allah belongs all honor, and to His messenger, and to the believers, but the hypocrites don't know, and all praise is due to Allah.' 

The president of neighbouring Chechnya, denied Islamists were responsible. Ramzan Kadyrov, said: 'One can say with certainty that the bandit and his patrons, in case he had any, do not have any direct or indirect connection to Islam.

'The North Caucasus has always been a region of close cooperation and mutual understanding between Muslims and Christians. So today, it is our duty to deter assaults on our heritage that instigators and Russia's enemies may make,' he said according to the Russian news site Tass.

He added: 'Those linked to him deserve to be severely punished.' 

The Russian RBK daily quoted an Orthodox priest saying the attacker opened fire on churchgoers following an afternoon service. 'We had finished the mass and were beginning to leave the church. A bearded man ran towards the church shouting "Allahu Akbar" and killed four people,' Father Pavel said. 'He was carrying a rifle and a knife.'

A fifth person later died in hospital.

The attack occurred as churchgoers celebrated Maslenitsa, a Christian holiday marking the last day before Lent according to the eastern Orthodox calendar. It is also exactly a month before Russia's elections on March 18 which sitting president Vladmir Putin is almost certain to win.

ISIS said it had established an affiliate in the North Caucasus in 2015 and has claimed responsibility for a number of attacks on police in Dagestan in the past couple of years involving guns and explosives. Local security forces are battling an Islamist insurgency but attacks on the region's minority Russian Orthodox population are rare.

Kizlyar is around 170 kilometres from Dagestan's capital Makhachkala and has a diverse population of 50,000 spanning 10 different ethnic groups. The small republic in the Caucasus mountains borders Chechnya, where Moscow has led two wars against separatists and radical religious groups since the 1991 Soviet collapse. It is one of the poorest and most unstable regions in Russia and has seen a large number of people join Islamic State.