Nairobi/Kinshasa - A rebel Tutsi general has called a ceasefire after four days of fighting in which his forces routed the Congolese National Army and came on the verge of taking the major eastern town of Goma.

General Laurent Nkunda told the BBC Wednesday night that he was calling a ceasefire to prevent panic in Goma and requested government forces do the same.

The French ambassador to the United Nations, Jean-Maurice Ripert, said he hoped the ceasefire "would stand" and called on Nkunda to cease hostilities from Thursday morning.

UN helicopter gunships and armoured vehicles have been supporting Congolese troops near Goma, the capital of North Kivu province, over the past few days as they struggle to contain Nkunda's National Congress for the Defence of the People (CNDP).

The army appeared to be in full retreat Wednesday, joining tens of thousands of refugees streaming toward Goma after the CNDP took control of small satellite towns.

Reports said Wednesday that the United Nations had ordered all local aid agencies to evacuate their staff from Goma as Nkunda's troops began to reach the city.

"The first of Nkunda's troops have arrived in Goma," Silvia Holten, spokeswoman for charity World Vision, told Deutsche Presse-Agentur dpa.

"There is heavy fighting, panic and people trying to flee," she said.

The UN peacekeeping mission in Congo has engaged the rebels over the past few days, pounding their positions with gunships, but their forces are stretched thin.

Alan Doss, the top UN envoy to the Democratic Republic of Congo, has appealed for more soldiers. Of the 17,000 UN troops in the sprawling country, 6,000 are deployed around Goma.

The CNDP and other groups in January signed peace accords designed to end sporadic clashes that occurred in 2007, four years after a war that began in 1998 officially ended.

But the CNDP and government soldiers have been involved in repeated clashes in the eastern provinces of North and South Kivu since late August.

Congo's government has accused neighbouring Rwanda of amassing troops on its border with a view to back Nkunda, who said he is fighting to protect Tutsis from armed Hutu groups.

There were some reports of firing across the Rwandan border on Wednesday, but they could not be verified.

Many Hutus fled to Congo after the 1994 massacres in Rwanda when Hutu militia and military killed an estimated 800,000 Tutsis and moderate Hutus in the space of a few months.

The UN Security Council condemned the recent fighting and called on Rwanda and Congo to defuse tensions.

The United Nations said about 250,000 civilians have fled the fighting since August, bringing the number of refugees in North Kivu to almost 1 million.

"The numbers of internally displaced are already huge, and it looks like it is going to grow," UN spokesman Ron Redmond said.

A spokeswoman for the aid agency Caritas said a humanitarian emergency was looming.

"It is increasingly difficult to provide food for the IDPs [internally displaced people]," Ursula Hartwig said. "... Some are threatened by starvation, and there is also a dangerous lack of clean water."

More than 5 million people are estimated to have died as a result of the long war in the resource-rich nation, most of them from hunger and disease.

The conflict is often referred to as the African World War, owing to the large number of different armed forces involved. (dpa)