JOHANNESBURG — Rwandan and Congolese rebels gang-raped 154 women and some baby boys over four days within miles of a peacekeepers’ base in eastern Congo, the U.N. said.

Will F. Cragin of the International Medical Corps said aid and U.N. workers knew rebels had occupied Luvungi town and surrounding villages the day after the attack began on July 30.

More than three weeks later, the U.N. peacekeeping mission in Congo has issued no statement about the atrocities and said Monday it is investigating.

At U.N. headquarters in New York, spokesman Martin Nesirky said Monday that a U.N. Joint Human Rights team verified allegations of the rape of at least 154 women by combatants from the Rwandan rebel FDLR group and Congolese Mai-Mai rebels in the village of Bunangiri.