A Nigerian government official said Thursday that the insurgent group Islamic State West Africa Province (ISWAP) is suspected as the perpetrators of a massacre at a Catholic church last week that left dozens dead. 

"We have been able to see the footprint of ISWAP in the horrendous attack in Owo and we are after them. Our security agencies are on their trail and we will bring them to justice," Interior Minister Ogbeni Rauf Aregbesola said Jun. 9 as reported by Reuters. 

In the June 5 attack, gunmen opened fire on Catholic worshipers attending Pentecost celebrations at St. Francis Xavier Catholic Church in Owo, Ondo State, in southwestern Nigeria.

Initial reports suggested that more than 50 people were killed, including children, and others injured. The official death toll for the attack currently stands at 40, with 61 injured people still in hospital, Reuters said. 

ISWAP is considered a breakaway faction of Boko Haram, another Islamic extremist terrorist group which has killed thousands of Christians and displaced millions of people in Nigeria and neighboring countries in recent years. ISWAP's leader at the time pledged allegiance to ISIS in 2015.

ISWAP has in recent years claimed to have carried out public executions of Christians and bragged of its actions in digital media. However, Ondo State, where the Pentecost attack took place, is far from ISWAP's usual area of operations in the north of the country. 

Pope Francis has expressed his “spiritual closeness” to Nigerian Catholics following the most recent attack, saying in a telegram that he was praying “for the conversion of those blinded by hatred and violence.”

More Christians are killed for their faith in Nigeria than any other country worldwide – at least 4,650 in 2021 and nearly 900 in the first three months of 2022 alone. Christian leaders and advocates continue to highlight and document the brutal ongoing persecution against Christians — often at the hands of their Muslim neighbors — in Africa’s most populous nation. Some aid organizations and experts are even assembling evidence that the killing of Christians in Nigeria constitutes a genocide

The country was, without explanation, in late 2021 delisted from the U.S. State Department’s list of countries with the most egregious religious freedom violations.

More in Middle East - Africa