The spokesperson says the rapes took place last month during an attack on the village of Bunangiri in North Kivu province by members of two armed groups, the United Nations News Service reports.
The groups were identified as insurgents loyal to ethnic Hutu fighters linked to the 1994 genocide in Rwanda and a local militia known as the Mai-Mai Cheka.
A spokesperson for the U.N. secretary-general said the women who were raped are receiving medical and psychological services.
More than 8,000 women were raped by warring factions in the Congo last year, the U.N. Population Fund reported.
Insurgents are thought to be responsible for most of the rapes but soldiers serving in the national army have also been implicated in sexual abuse, U.N. experts say.