OUAGADOUGOU, Burkina Faso — Gunmen burst into a church in northern Burkina Faso on Sunday and fatally shot four people, a security source said. It was at least the fourth attack on Christians in the West African country in the past month.

Other worshipers were wounded by the gunfire at the morning service at the church near the town of Titao, the source added.

No one has claimed responsibility for the attacks, which threaten to upend traditionally peaceful relations between the Muslim majority and Christians who make up a quarter of the country’s people.

The government has blamed unnamed terrorist groups operating in the country and Africa’s surrounding Sahel region.