Unidentified gunmen killed one pastor and five congregants in an attack on a Protestant church in northern Burkina Faso on Sunday, government spokesman Remy Fulgance Dandjinou said Monday.

Sunday's raid took place in the small northern town of Silgadji near Djibo, the capital of Soum province.

"The attack happened around 1 p.m., just as the faithful were leaving the church at the end of the service," a member of the church who did not want to be identified told AFP.

"The attackers were on motorbikes. They fired in the air before aiming at the members of the congregation," the witness added.

Burkina Faso, which boasts of a history of religious tolerance, has been beset by a rise in attacks as groups based in neighboring Mali seek to extend their influence over the Sahel, the arid scrubland south of the Sahara.

The government declared a state of emergency in several northern provinces bordering Mali in December because of deadly terrorist attacks, including in Soum, the region where Sunday's attack took place.

Spokesman Remy Fulgance Dandjinou said Monday that the latest attack was the first to target a church in the majority Muslim country where religious groups have historically lived together peacefully and frequently intermarried.

"Armed groups...have every interest in troubling or going against the good understanding between religions. We have observed this strategy in other countries in the region and in the world," said Rinaldo Depagne, West Africa Project Director at International Crisis Group.

Around 55 to 60% of Burkina Faso's population is Muslim, roughly 20-25% are Christian and the rest follow indigenous regions, according to the U.S. State Department.

Burkina Faso has suffered from increasingly frequent and deadly attacks attributed to a number of terrorist groups, including Daesh terror group's Greater Sahara branch.

The raids began in 2015 in the north before targeting the capital Ouagadougou and other regions, notably in the east.

A total of 350 people have been killed since 2015 -- mainly in hit-and-run raids -- according to an AFP tally.

The terrorist groups regularly target both Muslim and Christian clerics, mainly in the north.

In February, a Spanish Catholic priest, Father Cesar Fernandez, was killed in a raid attributed to terrorists in Nohao in the center of the country. He was returning from the adjoining country of Togo when it happened.

Fernandez, 72, had been working in Africa since 1982 for the Salesians of Don Bosco order.

In March, gunmen abducted Catholic priest Father Joel Yougbare from Botogui, near Djibo, in the north. The Catholic Church has not yet confirmed reports that his body has since been found.

Several imams, targeted by the terrorists for supposedly collaborating with authorities, have also been killed in the north, security sources say.

But religious leaders are not the only people targeted by the terrorists. On Friday, terrorists attacked a village school in Maitaougou, in the eastern province of Koulpelogo, killing five teachers and a municipal worker.

Human Right Watch's Sahel director Corinne Dufka recently said that the surge in terrorist violence and a government crackdown had "forced tens of thousands of villagers to flee since early 2019."

"Scores of people have been murdered in what amounts to a dramatic deterioration in the rights situation in northern Burkina Faso," she said last month.

Dufka said villagers live in fear as both the terrorists and government troops "have demonstrated utter disregard for human life."

Around 4.3 million people have been driven from their homes in the worsening violence that has engulfed the entire Sahel region, including 1 million over the past year, according to U.N. humanitarian officials.