Tutsi rebels have clashed with a local militia group in eastern Democratic Republic of Congo, the United Nations has said. spokeswoman for the UN mission in Congo (MONUC) said its peacekeepers were caught in the crossfire between the factions. The clash took place at Kiwanja near Rutshuru, a town which was captured last week by Tutsi fighters loyal to rebel General Laurent Nkunda in eastern North Kivu province. Gen Nkunda declared a ceasefire last week, halting an advance towards the North Kivu provincial capital of Goma that displaced tens of thousands of civilians. Goma lies 45 miles south of Rutshuru, where a unit of Indian and Uruguayan peacekeepers have a position. The UN spokeswoman said the firing occurred between the Tutsi rebels and Pareco Mai-Mai militia fighters, which like Nkunda's group had signed a peace deal for North Kivu in January. No more details were immediately available. Earlier, Gen Nkunda threatened to take his eastern guerrilla war westwards to the capital Kinshasa unless the government agreed to talks on the country's future. Defiant in the face of international moves to end the conflict in east Democratic Republic of Congo, Gen Nkunda rejected complaints by human rights groups against him, saying he "didn't give a damn" about the International Criminal Court (ICC). "I've done no wrong to my people ... nobody can reproach me for anything," the rebel chief said. Gen Nkunda belongs to and defends the Congo's Tutsi minority but also demands a better government for the whole country. The United Nations and foreign aid groups are now scrambling to address a humanitarian emergency described as "catastrophic" by relief workers in a country where more than five million people have died in a decade from conflict, hunger and disease. A 12-vehicle relief convoy escorted by UN troops has been allowed to pass through the frontline between the Congolese army and Tutsi rebels. It is the first humanitarian aid to be delivered behind rebel lines since fighting broke out in August. Tens of thousands of people have received little food aid since they fled their homes a week ago. A UN official stressed that medical supplies and water purifying tablets were the priority in the shipment and said a second convoy would deliver food for some of the 250,000 refugees displaced by fighting in this central African nation. In Kibati, two miles north of Goma, some food from USaid was distributed at the UN-run camp where internally displaced people were handed high energy biscuits. USaid production manager Fred Wakige said: "We are giving 500 grams to each child, and we were going to give less to the children over one metre tall but on arrival we noticed that the bigger children were hungrier than the smaller, weaker ones, so we made the decision to give biscuits to the bigger, older children too." The conflict is fuelled by festering ethnic hatred left over from Rwanda's 1994 genocide and DRC's civil wars from 1996-2002. Gen Nkunda claims the Democratic Republic of Congo's government has not protected ethnic Tutsis from the Rwandan Hutu militia that escaped to there after helping slaughter a half-million Rwandan Tutsis. The UN peacekeeping mission in the country is its largest in the world, yet only 6,000 peacekeepers of the 17,000-strong mission are in the east because of unrest in other provinces.