"The abuse of children by those sent to help is a significant and painful issue and one that U.N. peacekeeping has and will continue to address candidly, comprehensively and robustly," Ban said in the statement read by Montas. "Even one incident is too many."

YOUNG GIRLS

More than half of the participants in the study identified incidents of sexual touching and forced sex. Of these, 18 and 23 percent respectively recalled 10 or more such incidents.

"They especially ask us for girls of our age. Often it will be between eight and 10 men who will share two or three girls. When I suggest an older girl, they say that they want a young girl," a 14-year-old boy who works at a peacekeeping camp i...

"The abuse of children by those sent to help is a significant and painful issue and one that U.N. peacekeeping has and will continue to address candidly, comprehensively and robustly," Ban said in the statement read by Montas. "Even one incident is too many."

YOUNG GIRLS

More than half of the participants in the study identified incidents of sexual touching and forced sex. Of these, 18 and 23 percent respectively recalled 10 or more such incidents.

"They especially ask us for girls of our age. Often it will be between eight and 10 men who will share two or three girls. When I suggest an older girl, they say that they want a young girl," a 14-year-old boy who works at a peacekeeping camp in Ivory Coast told the Save the Children research team.

And the report said official U.N. statistics appeared to underestimate the scale of abuse, probably because so much of the exploitation was not reported by victims.

"Clearly there is a significant disparity between the low levels of abuse cited in these statistics and the high levels suggested in field investigations and other evidence," it said.

Save the Children said there were many reasons why abuse was not reported: fear of losing material assistance, threat of retribution, stigmatization, negative economic impact, lack of legal services, resignation to abuse, lack of information about how to report abuse and, crucially, lack of faith in a response.

Anecdotal evidence from all 38 focus groups suggested there was an endemic failure to respond to reports of abuse.