''We strongly condemn this senseless act against aid workers who were there to improve the lives of the must vulnerable populations,'' the UN agency said in a statement.

UNICEF said its aid worker was killed on Feb. 25 along with five education workers ''while traveling in the northwestern region of the Central African Republic, near Markounda.’’

''We offer our deepest condolences to the families and the colleagues of the victims,'' it added. 

Central African Republic has been wracked by violence since Seleka rebels ousted then President Francois Bozize in 2013.

Fierce fighting has continued between the Muslim Seleka and Christian anti-Balaka rebels, forcing nearly half the country's population to depend on humanitarian assistance, according to the UN.