A priest was one of those killed on 1st May at Our Lady Fatima Church, just four years after 15 people were killed from the same church.
2000 people had gathered for the service in Bengui, the capital of Central African Republic (CAR), when armed men threw grenades and fired on the church.
Several of those killed or injured were trapped in the church compound as the gunmen attacked and were unable to flee until police intervened.
Local sources report that constant gunfire was heard in and around KM5 district from the time of the attack until 3pm.
The Chancellor of the Archdiocese of Bangui has identified Father Albert Toungoumale Baba as the priest killed at the church.
After attacking the church, the perpetrators moved into neighbouring districts, looting shops and homes and attacking civilians. An Evangelical church member was killed outside his home.
Father Moses Otii, the parish priest of Our Lady of Fatima told Catholic charity Aid to Church in Need: "I saw three hand grenades thrown in front of the Church, but thank God in an area without people, and a grenade thrown in among many people gathered in the open air within the church's compound."
He added that in the commotion, some ran and hid but others couldn't: "a lady had both legs cut off by the grenade, she couldn't move. It was a commotion with people running and people crying."
Chief Executive of Christian Solidarity Worldwide, Mervyn Thomas said: "We extend our condolences to the parishioners of Our Lady Fatima Church, to the family of Albert Toungoumale Baba and to all those who have been bereaved."
"The attack on a place of worship not only violates the right to freedom of religion or belief, but also threatens the social fabric of the community that religious leaders of all faiths have worked to maintain throughout the recent conflict.
The attack was reportedly perpetrated by armed elements from the KM5 district of Bangui, which is predominantly a Muslim neighbourhood.
The day after the deaths, protests were organised by residents of the district.
Stay up to date with the latest news stories from a Christian perspective. Sign up to our daily newsletter and receive more stories like this straight to your inbox every morning.