Suspected jihadists killed 15 Christians at a baptism that was ambushed in Burkina Faso last Tuesday.
The attack occurred in Oudalan province close to the Mali border, International Christian Concern (ICC) reports.
Moha AG Agraz, who has been in contact with local residents, told ABC News that people were "shocked" over the incident.
Although no group has claimed responsibility for the attack, the region has seen increasing levels of violence at the hands of al-Qaeda and the so-called Islamic State.
"Burkina Faso, once seen as a harmonious nation of religious tolerance, has been infiltrated by jihadist and militia groups known to commit grave acts of violence and human rights violations," ICC said.
"Extremists have conducted numerous attacks on both civilian and government targets, many times focusing on Christians, their leaders, and places of worship.
"Please pray for our brothers and sisters in Burkina Faso and ask the Lord to protect Christians living in these persecuted areas."
The attack occurred on the same day as Release International warned that Burkina Faso is on track to become the next Nigeria, where Islamist militants and radicalized herders have killed thousands.
"What began in the Middle East is spreading. Today Africa has become the prize for violent jihadists set to impose their firebrand version of Islam on the world," the organization's Andrew Boyd wrote.
"Partners of UK-based Release International say the jihadists have been deliberately targeting pastors and priests, forcing churches in many areas to close their doors and meet in secret.
"During their attacks, they would stop villagers and demand to know their religion. Those who said they were Christian would be killed immediately, while those of other faiths would be allowed to return home unharmed.
"But Christians are not the only target. What drives the jihadists is the desire to purge Islam of compromise and to rid the land of infidels. This thinking, taken to extremes, sets Sunni against Shia, radical against moderate, tribe against tribe and Muslim against other faiths.
"In Burkina Faso, the militants are also attacking Muslim imams who oppose their beliefs. And in areas under their control in Mali they have imposed a harsh version of sharia (Islamic law)."