Women and children are being gang raped in northeastern Democratic Republic of Congo in what amounts to crimes against humanity, Medecins Sans Frontieres said on Thursday.

The aid group called for all forces deployed in the Ituri region, including U.N. peacekeepers who killed an estimated 50 militiamen in a battle on Tuesday, to protect the tens of thousands of Congolese civilians fleeing violence.

“These rapes are often extremely violent and committed in the presence of the victim’s family who is also traumatised,” Francoise Duroch, coordinator of MSF’s programme for victims of sexual violence, told a news briefing.

“The cruelty associated with these rapes make us think of crimes against humanity.”

MSF has treated 2,567 rape victims, from 4-months to 80-years old, at its hospital in Bunia, capital of Ituri district, since June 2003. But the true number could be up to 50 times higher as many decline to seek help due to the stigma, it said.

Some 77 percent of the women have been raped by two or more assailants, according to Roman Gillies, president of MSF International, which has recently moved to Geneva from Brussels.

Ethnic warfare marked by atrocities has killed more than 50,000 people in Ituri since 1999.

An upsurge in clashes since January has escalated further since nine Bangladeshi U.N. troops were killed a week ago.

MSF has partially suspended its aid activities in four camps in the region, but is not considering withdrawing for now, according to Gillies.

“We see people trickling into (Bunia) hospital with machete wounds telling stories of massacres. However we think it is the tip of the iceberg,” he said.

The Australian, who spent a month treating war victims in Bunia, spoke of a 14-year-old girl gang raped by militias who used sticks, guns and knives to abuse her.

“We needed to repair the physical damage. But all the other damage we can’t do much about,” he said.

MSF also voiced concern that malnutrition is rising, with one in four children in the area showing signs.

Abiy Tamrat, head of the emergency desk at MSF Switzerland, said the crisis was becoming like 2003 when “lawlessness and revenge was the norm rather than the exception”.

“We are concerned that the proportion of malnutrition could increase now that aid has been interrupted. Unless we have the kind of security whereby we can provide care, things will deteriorate in these camps,” he added.