United Nation aid workers say that up to 30,000 civilians have been driven out of their homes and are in need of food and shelter following fighting between rebel and government forces in Congo's lawless east.

Returning from an assessment mission in and around the town of Kalehe, about 35 kilometers north of the town of Bukavu, aid workers have said that up to 30,000 civilians have fled their homes and are in need of food and shelter following recent fighting in eastern Congo.

The aid workers who visited Kalehe said they found pockets of civilians who fled their homes and sought shelter on the shores of Lake Kivu.

Kalehe and the hills surrounding the town have been the scene of clashes over the last two weeks as thousands of government soldiers advance north toward the base of dissident army officer General Laurent Nkunda.

Since launching an armed uprising in May, General Nkunda and several thousand men seized Bukavu, holding the strategic border town for a week, before withdrawing to a lakeside base 100 kilometers to the north.

Jean Marc Cordaro, the head of the U.N. Office for the Coordination of Humanitarian Affairs in Bukavu, said that agencies were planning their response and would try to deliver assistance by early next week. He said the estimate of 30,000 displaced persons was given to humanitarian workers by local authorities.

The United Nations warns fighting in eastern Congo is creating one of the world's worst humanitarian disasters, with more than three million people relying humanitarian aid.

General Nkunda's uprising has undermined the Congo government's attempt to secure lasting peace, following the end of a five-year war that involved six neighboring countries and caused at least three million deaths, mostly from hunger and disease.

The country's transitional government is due to lead Africa's third-largest nation to elections in a year's time, but deep divisions remain as a lack of trust between the political players and a reluctance to relinquish control over traditional fiefdoms delay the move towards democracy.