United Nations staff turned up a case of sexual abuse of a girl by a French soldier in Central African Republic, the U.N. human rights chief said Thursday, in the latest claim of sexual abuse by foreign troops in the poor, unstable African country.

France's military has already been rocked by accounts by children as young as 9 of French soldiers giving them food or water in exchange for sex. While French authorities knew of those cases last summer, they only came to light publicly after Britain's Guardian newspaper reported them in April. No arrests have been made.

On Thursday, U.N. High Commissioner for Human Rights Zeid Ra'ad Al Hussein announced during a trip to CAR that the alleged victim in the latest case was in her teens during the abuse about a year ago. She gave birth to a child in April, and has filed a paternity claim with local authorities.

France sent troops to stabilize CAR in December 2013 after violence erupted between Muslims and Christians, killing at least 5,000 people. A U.N. peacekeeping mission has since been deployed as well. Those peacekeepers have been hit by more than a dozen allegations of sexual abuse. U.N. Secretary-General Ban Ki-moon last month took the unprecedented step of firing the mission's leader.

"This is the latest in a series of appalling allegations of sexual exploitation and abuse by foreign troops in CAR," Zeid said of the new allegations, noting that the French troops are separate from the peacekeeping mission. "We simply have to find ways to prevent such odious acts being committed by any soldiers anywhere who are supposed to be protecting vulnerable populations."

He said French authorities have been informed, and that countries that contribute troops are obligated to quickly investigate such claims.