An attack on a Catholic church in Nigeria, West Africa, has killed as many as 100. Dozens of children and pregnant women were among the dead, said Oluwole Ogunmolasuyi, a local politician in southwestern Ondo state, on Monday.

Heavily armed perpetrators stormed St. Francis Church in the city of Owo on Whitsunday during a service, shot indiscriminately at the faithful and set off explosives. “It was barbaric, we’ve never seen anything like it,” Ogunmolasuyi said after visiting the church and a hospital treating scores of the injured. “The number of victims is between 70 and 100,” says Ogunmolasuyi.

President Muhammadu Buhari condemned the attack. “This country will never give in to evil and evil people, and darkness will never conquer the light,” Buhari was quoted as saying on Twitter.

Pope Francis promised his prayers to the victims and their families. “His Holiness was deeply saddened to learn of the horrific attack at St. Francis Church in Owo,” said a telegram from the Holy See to the Bishop of Ondo State. The Bishop for Foreign Affairs of the Evangelical Church in Germany, Petra Bosse-Huber, wrote in a statement: “We pray for the people in Nigeria who have repeatedly had to suffer such senseless violence for years.”

Ondo Governor Rotimi Akeredolu called the attack “disgusting and satanic,” adding that “it is a calculated attack on the peace-loving people of Owo.” The exact number of victims and which group is behind the attack remained unclear. Authorities initially spoke of up to 50 dead on Sunday.

The government has launched an investigation. “The attack is undoubtedly terrorist in nature. The scale and brutality suggest it was carefully planned and not impulsive,” said Eric Humphery-Smith, an analyst at security consultancy Verisk-Maplecroft. According to Humphery-Smith, the background to the attack is growing ethnic and religious tensions in Africa’s most populous country with a population of around 206 million.

The security situation in Nigeria has long been considered tense. The most populous country in Africa recently experienced a new wave of violence. However, it is the first time that a major attack has been carried out on a church in the predominantly Christian south. So far, no one has claimed responsibility for the attack.

EU foreign policy chief Josep Borrell was shocked by the attack. “The unacceptable attacks by non-state armed groups are being repeated in different parts of Nigeria and the senseless violence has now reached the previously peaceful state of Ondo,” the Spaniard said. The EU is in solidarity with the people in the state.