The government-owned daily al-Anbaa newspaper quoted an unnamed security source in Kassala state as saying 50,000 refugees fleeing the war between Ethiopia and Eritrea had entered Sudan on Thursday evening.

According to the Akhbar al-Youm daily, the refugees -- women, children, and sick and elderly people -- have been put in camps in the areas of al-Lafa, Galsa and Awaad in Kassala.

The daily quoted state Governor Ibrahim Mahmoud Hamid as saying citizens there had donated large quantities of food and medicines as well as water tankers for the camps.

The governor said the task was too much for his government and he appealed to local and international humanitarian organisations for assistance.

A government delegation headed by Assistant Interior Minister Ahmed Mohamed al-Ass and the representative of the U.N. High Commissioner for Refugees (UNHCR) in Sudan, Wenceslaus Romani Urasa, left Khartoum on Friday for Kassala to assess the situation.

In Geneva, the UNHCR said up to 18,000 Eritrean civilians and soldiers had fled into Sudan since Thursday to get away from the fighting. The soldiers were being disarmed by the Sudanese army.

``Now we are hearing up to 80,000 could be about to cross, but we cannot confirm that figure,'' UNHCR spokesman Ron Redmond said.

The new influx of refugees from Eritrea comes at a very bad time for Sudan and the UNHCR, which had reached an agreement with the Sudanese and Eritrean governments for the voluntary repatriation of some 160,000 Eritrean refugees from Sudan.

These refugees, some of whom have lived in Sudan for over 30 years, are in 23 camps in various parts of eastern and central Sudan. The repatriation had been due to start this month and it was not immediately clear how the latest refugee influx would affect the plan.

The United Nations said on Friday thousands of Eritrean civilians and soldiers were crossing into Sudan to escape renewed fighting with Ethiopian forces. The Geneva-based UNHCR said up to 18,000 Eritreans have entered Sudan since Thursday.

"Now we are hearing up to 80,000 could be about to cross but we cannot confirm that figure," UNHCR spokesman Ron Redmond said.

He said "a fair number" of Eritrean soldiers were among the arrivals and were being disarmed by the Sudanese army.

"The efforts now are being directed towards these new arrivals and the potential outflow that we could be seeing along that border," Redmond added.

Ethiopia and Eritrea, two of the world's poorest countries, are at war over a border dispute. An uneasy stand-off ended a week ago when Ethiopia launched an offensive.

Redmond said hundreds of thousands of internally displaced people were reported to be fleeing north following an attack on Barentu, a vital Eritrean supply centre for the western front 70 km (45 miles) to the south.

The Eritrean Relief and Refugee commission has said over half a million people had been displaced since last Friday.

Aid officials said the war was complicating a food operation to alleviate the effects of drought, and could deter donors.

The World Food Programme (WFP) put the number of Eritreans displaced by the attack on Barentu at 340,000.

Spokeswoman Christiane Berthiaume of the U.N. food agency said that the Eritrean authorities estimated the total number of Eritreans displaced by the war at 1.5 million.

"That is a very high figure. Eritrea's population is four million," she said. "The WFP estimates that the food needs of the refugees will be very large," she added. "We are very concerned about the situation."

The exodus into Sudan came just days before the planned start of the U.N. repatriation of Eritrean refugees in Sudan.

Reporting from Kassala, the official Al Anbaa daily quoted an unnamed security source as saying about 50,000 Eritreans had crossed the border at Luffah by late Thursday.

The paper's source added that "a tremendous influx is continuing" from Eritrea's Gash province.

Al Rai Al Aam daily quoted Kassala state Governor Ibrahim Mahmoud Hamid as saying security authorities had been disarming Eritrean soldiers who crossed the border along with civilians, including women, children and elderly, after the fall of Barentu to the Ethiopians earlier this wake.

Hamid said "a maximum state of mobilisation" had been declared and committees have begun taking care of the refugees with the assistance of staff of the UN High Commissioner for Refugees.

The governor has appealed to the international community and to humanitarian organisations for immediate assistance to meet the "worsening situation on the border".

He said special camps have been prepared for the fleeing soldiers who have already arrived in Sudan and those who are at the crossing points waiting to come into the country.

Akhbar Al Youm daily reported that Kassala citizens had donated large quantities of food and medicines but it quoted the governor as saying the situation is beyond the resources of his state.