Humanitarian officials warn a crisis in eastern Congo's war-torn North Kivu Province is deepening with each passing day. A new eruption of fighting between rebels and the Congolese army has sent thousands of civilians streaming over mountain roads for the relative safety of the capital city, Goma. And, aid access to tens of thousands of other people has been cut. Noel King has this report from Masisi.

Fierce eruptions of violence in eastern Congo are crippling the delivery of humanitarian aid.

A recent World Food Program convoy, bound for Masisi, became stuck on muddy roads, as fighting between forces loyal to dissident General Laurent Nkunda and the Congolese army erupted a few kilometers away.

Gaining access to vulnerable people is the newest front in an increasingly complex emergency in eastern Congo's North Kivu Province.

"We just can't reach people like we used to," said Aya Shneerson, director of the World Food Program in north and south Kivu Province. "So, in some parts, we have tens of thousands of people who have fled conflict, who are living in deplorable conditions, who really need our help and we just can't get there."

Fighting in rural areas has caused thousands of people to flee their homes, with more leaving home every day.

As the World Food Program convoy headed into a mountain pass, the roads swelled with civilians fleeing Karuba. None of the displaced people carried much more than a bag of cassava plants and an umbrella. This will have to sustain them until food aid arrives in the squalid camps for the displaced that have sprung up outside Goma.

Fura Nyamarihu was among those fleeing Karuba. She says the fighting started two days ago and that the soldiers of Laurent Nkunda are looting food from people's houses.

Days later, 34 tons of food aid were delivered to some 20,000 displaced people in Masisi. But the WFP Convoy was cut off at the town, because of fighting along the roads.

In Masisi, an anti-United Nations riot erupted. Residents of the town, mostly secondary school students, chased after the trucks of U.N. peacekeepers, hurling rocks at them.

One protester, Kibanga Kibuya, explained why the riot began. He accuses the United Nations of giving Laurent Nkunda ammunition and uniforms.

The United Nations strongly denies any connection to Nkunda. Officials said the riot was likely incited by members of one of eastern Congo's numerous armed militia groups.

Congolese police fired into the air to disperse the protesters, but not before the young rioters reached the U.N. base and demanded to talk to officials there.

After an hour, the United Nations dispatched two helicopters from Goma.

Rioters retreated into their homes and the streets were quiet again.

An estimated 370,000 people have fled their homes since fighting erupted between Nkunda's forces and the Congolese army, in December of 2006.

Congo, a resource rich but chronically troubled nation, has several armed militia groups operating in the eastern provinces.

Following a 2006 election, Congolese officials asked militias to integrate into the regular army.

Nkunda's forces, among others, have refused. Nkunda charges that Congo has not done enough to rid the east of Hutu militias, with links to neighboring Rwanda's 1994 genocide.

Nkunda, an ethnic Tutsi, says he is trying to protect Congo's Tutsi population.

But, by many accounts, his rebellion is unpopular among a civilian population already exhausted by years of war.