French investigators have dropped an investigation of alleged child sexual abuse by French soldiers in Central African Republic.

A judicial official said Monday that investigating judges made the decision last week. The official, who was not authorized to be publicly named discussing the case, would not give their reasons.

French news reports say the investigators concluded they didn't have enough evidence to bring charges.

About 15 children told United Nations investigators they were sexually abused by French troops in the Central African Republic's capital, Bangui, in 2014. The abuse allegedly took place in or near a camp for displaced people near M'Poko airport, which the French soldiers were assigned to protect.

France, Central African Republic's former colonial ruler, sent troops in 2013 amid violence between Christians and Muslims. A U.N. peacekeeping mission began the next year.