The New York Times reported that the Democratic Forces for the Liberation of Rwanda, or F.D.L.R., gang-raped at least 150 women in July and August during a weekend raid on a community of villages in eastern Congo.

The F.D.L.R. is an ethnic Hutu rebel group, which began as a gathering of fugitives of the Rwandan genocide.  It has been terrorizing the hills of eastern Congo for years, preying on villages in a quest for the natural resources beneath them.

The raided villages are near the mining center of Walikale, known to be a rebel stronghold, and are “very insecure,” said Stefania Trassari, a spokeswoman for the United Nations Office for the Coordination of Humanitarian Affairs. “Rape is something we get quite often.”

But she and other United Nations and humanitarian officials said that this attack was unusual because of the large number of victims and the fact that they were raped by more than one attacker simultaneously.

On the evening of July 30, armed men entered the village of Ruvungi, in North Kivu Province.

“They told the population that they were just there for food and rest and that they shouldn’t worry,” said Will F. Cragin, the International Medical Corps’ program coordinator for North Kivu, who visited the village a week after their arrival.

“Then after dark another group came,” said Mr. Cragin, referring to between 200 and 400 armed men who witnesses described as spending days and nights looting Ruvungi and nearby villages.

“They began to systematically rape the population,” he said, adding, “Most women were raped by two to six men at a time.”

The attackers often took the victims into the bush or into their homes, raping them “in front of their children and their families,” Mr. Cragin said. “If a car passed, they would hide.”

The rebels left on Aug. 3, he said, the same day the chief of the area traveled through the villages and reported horrific cases of sexual violence. “We thought at first he was exaggerating,” Mr. Cragin said, “but then we saw the scale of the attacks.”

Miel Hendrickson, a regional director for the International Medical Corps, which has been documenting the rape cases, said, “We had heard first 24 rapes, then 56, then 78, then 96, then 156.”

“The numbers keep rising,” she said. The United Nations maintains a military base approximately 20 miles from the villages, but United Nations officials said they did not know if the peacekeepers there were aware of the attack as it occurred. A United Nations military spokesman, Madnoje Mounoubai, said information was still being gathered.

However, according to a subsequent New York Times report, U.N. officials had been warned about the rape much earlier than officials originally said, according to an internal U.N. e-mail and a humanitarian bulletin.

The United Nations’ beleaguered peacekeeping mission in Congo had been harshly criticized since the news broke that it did not respond to the F.D.L.R. attack.  The mission was stationed around 30 kilometers away, but none went to the area until Aug. 2, when a patrol passed through one of the stricken villages, though according to United Nations officials, none of the villagers came forward about the rapes.

Analysts and some officials within the United Nations say the rapes in Mpofi area were not the first time that the United Nations mission in Congo delayed in sharing information about widespread atrocities.

For the full New York Times articles, click here and here.  For a U.N. report about how it is going to respond to the situation, click here.