Margot Wallstrom, the secretary-general's special representative on sexual violence in conflict, said in a statement on Thursday that women and girls "are subjected to attacks, including rape, by armed militants and bandits" on the journey to the Kenya border.
Once in Kenya or at the Dadaab refugee camp, she said, "their hopes of finding a safe haven are often overshadowed by new dangers and hardships, including the risk of rape".
Wallstrom said her office also has received "alarming information about alleged rapes" by government-allied militia in south-central Somalia and of al-Shabaab Islamist militants abducting girls for forced marriage to fighters.