Doctors Without Borders says it has suspended activities in a Central African Republic town where gunmen attacked its hospital.
The aid group, known by its French acronym MSF, says in a statement that 16 civilians including three local staff members were killed during the incident Saturday in the northern town of Boguila. Earlier reports put the death toll at 22.
MSF says former Seleka rebels surrounded the hospital grounds while the aid group's officials met with local community leaders. It says some of the gunmen robbed the MSF office at gunpoint, while others opened fire on benches where the meeting was taking place, killing or wounding participants.
The aid group says it has withdrawn key staff from Boguila and will examine whether it can continue operations there and in other parts of the C.A.R.
The country has endured more than a year of rampant violence, much of it sectarian.
On Sunday, international peacekeepers evacuated some of the last remaining Muslims from the C.A.R. capital, Bangui. The 1,300 people had been surrounded by largely Christian "anti-balaka" militants for months.
Afterward, Christians looted houses and a mosque in the Muslims' former neighborhood.
Muslims have been fleeing Christian-majority areas of the C.A.R. to escape anti-balaka attacks.
The militias formed in response to a wave of killing and looting by Seleka after the group toppled the president in March 2013. Seleka was forced out of Bangui earlier this year.
Some 2,000 French troops and 5,000 African peacekeepers have attempted to halt the violence, with little success. The U.N. Security Council recently authorized a larger peacekeeping force for the troubled country.