UN Secretary-General Ban Ki-moon is "shocked to the core" by allegations of sexual abuse by UN peacekeepers and French troops in the Central African Republic, his spokesman said Thursday.
"We must face the fact that a number of troops sent to protect people instead acted with hearts of darkness," UN spokesman Stephane Dujarric said.
The United Nations is investigating new claims that troops from Burundi and Gabon serving in its peace force in the Central African Republic sexually abused women and girls.
UN teams sent to the Kemo region of the strife-torn country also received accounts that French troops from the Sangaris force coerced girls into engaging in bestiality in return for small amounts of money.
UN rights officers have interviewed 108 victims of sexual abuse, "the vast majority" of whom are girls, said Dujarric.
"We are talking about women and young children who have been traumatised in the worst imaginable way," he added.
Ban described the latest reported cases as "despicable, depraved and deeply disturbing" and once again urged troop-contributing countries to take action to prosecute those responsible for the serious crimes.
Under UN rules, the responsibility for investigating and prosecuting peacekeeper sexual abuse lies with the countries that contribute the troops and police to the peace missions.
In a first, Dujarric said the United Nations would carry out a joint investigation withBurundi and Gabon of the allegations that took place between 2013 and 2015.
France pledged to "shed full light" on the allegations, with Ambassador Francois Delattre saying the new cases were "sickening and odious."
AIDS-Free World, a civil society group that tracks peacekeeper sex abuse cases, said three girls told a UN rights officer that in 2014 they were tied up and undressed by a Sangaris commander inside a camp and forced to have sex with a dog.