More than 55,000 refugees from eastern Democratic Republic of Congo have arrived in Uganda after fleeing a rebel attack, Red Cross officials said, although the rate of new arrivals has begun to slow down.

The town of Kamango in the northernmost part of Congo's North Kivu province was attacked and briefly occupied Thursday by a Ugandan-led rebel group, the Allied Democratic Forces (ADF).

Refugees have streamed across the border into western Uganda's Bundibugyo district since the attack on Thursday, although the numbers of new arrivals crossing on Sunday had slowed to a trickle.

It was reported to be calm on Sunday, and some refugees said they wanted to return home.

"Given such numbers there is need for urgent humanitarian assistance, as some of the refugees are sick and have left all their belongings in Congo," Uganda Red Cross official Catherine Ntabadde said.

Tallies made late Saturday estimated 55,000 refugees had crossed the border, up from 30,000 the day before, she added.

However, thousands still crowded into the grounds of schools in Bundibugyo - about 20 kilometres from the border with Congo - offered as a temporary shelter, with many building makeshift shelters or simply sleeping out in the open.

"Many new arrivals are also reported to be staying in the community," said UN refugee agency official Karen Ringuette.

"New arrivals are staying at five primary schools and various other sites."

The Red Cross are working with the United Nations and other aid agencies to set up a camp further inside Uganda, although many refugees appeared reluctant to leave.

"The (Ugandan) government has found a transit camp 8 kilometres from Bundibugyo town... there we can start registering them afresh," Ms Ntabadde said.

Long lines of refugees crossing into Uganda seen in recent days had declined, and that large crowds were waiting to return back into Congo.

"I want go to back home, because we are hungry here, and I want to make sure my belongings at home are safe," a man who gave his name only as Mateso said.

"It is better that we go back to the land we know than to go far away to a camp in Uganda."

In Bundibugyo, refugees carried their belongings piled on their heads, including rolled-up mattresses, cooking pots and chickens.

Some refugees complained that while they had seen food delivered by the UN World Food Programme (WFP), they had not yet received any.

"We have nothing to eat, because when we ran from the rebels we could only grab what we had around us and could carry," Teresa Zaki, who fled from Kamango on Thursday, said.

Residents of Kamango said that public buildings and the hospital had been pillaged, while local chief Jean-Paul Saambili said that nine people were killed by the rebels.

However, Mr Saambili said Kamango was calm Sunday and he "had not heard gunfire for three days".

Congolese army spokesman for the North Kivu region Olivier Hamuli said troops were "hunting" down ADF fighters.

Mr Hamuli claimed the attack on Kamango was driven by rebel desperation "to survive", pointing out that they had looted health centres of medicines.

UN agencies have begun delivering kits to start digging latrines, as well as a tanker to deliver clean water.

WFP said it had delivered 54 tonnes of food on Saturday - enough to feed 20,000 people for five days - and that more aid was due today.

AFP