Three mass graves have been discovered in an eastern Congo village where fighters loyal to a rebel warlord recently battled government troops, the U.N. said Friday.

Maj. Gabriel De Brosses, a spokesman for the U.N. peacekeeping force in Congo, said the graves were found Monday in Rubare, a village about 40 miles north of the regional capital, Goma. He did not know how many bodies had been found or who killed the victims.

Rubare was controlled by fighters loyal to former army Gen. Laurent Nkunda until clashes broke out earlier this month between his men and the army.

Michel Bonnardeaux, a spokesman for the U.N. mission in Congo, said the graves were found by residents, who reported them to U.N. officials.

Once controlled by rival rebel factions who eventually signed a peace deal in 2002 to end a four-year war, eastern Congo has been wracked by fighting between local militias, renegade soldiers and the army for years.

Nkunda quit the army after the war and launched his own rebellion, claiming the country's transition to democracy was flawed and excluded the country's ethnic Tutsi minority. Nkunda has also said he is fighting to protect ethnic Tutsis from Rwandan Hutu rebels who took refuge in eastern Congo following Rwanda's 1994 genocide.

On Thursday, President Joseph Kabila called on fighters loyal Nkunda to join the national army, warning the government would no longer tolerate militias and needed to re-establish authority in the lawless east.

The World Food Program said Friday it had delivered emergency food rations to about 35,000 people at a camp at Muganga just north of the regional capital, Goma.

But "poor security has severely limited access beyond Mugunga to the worst-affected areas," the U.N. agency said. In one district, "at least 7,000 people are believed to be living in the bush in urgent need of food."

Tens of thousands of people have fled the latest round of violence, bringing to nearly 1 million the number of people displaced from years of conflict in the eastern provinces of North and South Kivu, WFP said.