BUKAVU, Zaire -- Panic-stricken aid agencies were trying Friday to persuade the Zaire government to reconsider plans to close the frontier with Rwanda, halting the flood of Hutu refugees into the packed town of Bukavu.


Abou Moussa, emergency coordinator for the United Nations High Commissioner for Refugees, said he was in constant contact with the local governor and was doing all he could to convince Kinshasa that the decision to close, announced unexpectedly Friday, would be a mistake.


"This was a decision taken unilaterally and without any coordination. We are continuing to negotiate and we are continuing to discuss," he said.


The UNHCR said in Geneva that Rwandan refugees were pouring over the border into Zaire at the rate of 30 per minute and might total 15,000 by the end of the day.


It also said Zaire had informed the agency a few days ago it would close the border if an exodus resembled a "Goma-like situation" -- a reference to the Zairean border town where 800,000 people are stranded in disease-ridden camps.


Plans to close the two main bridge crossings linking Bukavu to the Rwandan town of Cyangugu -- communicated to the UNHCR representative in the capital by Zaire's Interior Minister Gustave Malumba -- came as a complete surprise to aid officials.


They said that with daily new arrivals in Bukavu now touching 11,000, shutting the border risked sparking a mass panic among Hutu refugees fleeing Rwanda's southwestern protection zone ahead of a French troop pullout on August 22.


Given the porous nature of the border, refugees would continue to arrive but would be dispersed across the frontier region, complicating the task of feeding and providing shelter, they said.


"The border is long and convoluted. There's an infinity of crossing points and it's always possible to come across by boat," said UNHCR's Peter Romanovsky. "The effect would be to divert the flow rather than halt it."


Worried aid agencies on Friday sent teams to the Ruzizi border post, which has been reinforced by Zairean commandos ahead of an eventual closure, in search of details. But no date or time for the closure has been announced. As of midday, the refugees were still being allowed across the rickety bridge.


Moussa admitted on Friday that the influx had reached a "very, very alarming" level. Bukavu already holds 320,000 refugees who fled Rwanda when the former government left Gisenyi and the aid agencies are running out of suitable sites for refugee camps in the heavily cultivated farming region.


If reassurances from the Tutsi-dominated government in Kigali continue to fall on deaf ears, they fear a repeat of the catastrophic influx into Goma in eastern Zaire last month which climaxed with thousands dying of dysentery 'and cholera.


But many said privately they believed Zaire was simply trying to attract international attention to its plight, and any closure would be shortlived.