U.N. Considers Withdrawal of Force in Rwanda : Central Africa: Belgium will pull out troops. Move prompts concern for peacekeepers.

The United Nations prepared Wednesday for a possible withdrawal of all its peacekeepers from the bloodied chaos of Rwanda after Belgium--the former colonial power now targeted by some of the killers in the Central African nation--decided to pull out its key contingent of 440 troops.

In Rwanda, “the continued discharge by (the U.N. peacekeeping force) of its mandate will become untenable,” Secretary General Boutros Boutros-Ghali wrote the Security Council, “unless the Belgian contingent is replaced by another equally well-equipped contingent or unless the government of Belgium reconsiders its decision to withdraw its contingent.”

Ambassador Colin Keating of New Zealand, the council president this month, said the world body will have to decide in the next few days what to do about the force of 2,500 sent to Rwanda last year to supervise a cease-fire and elections.

Keating also reported that Rwanda’s rebels and representatives of the country’s interim government agreed to meet today to negotiate a truce under U.N. auspices.

While U.N. diplomats and officials in New York pondered whether to abort the mission, depressing reports continued to cascade from Rwanda:

* Unidentified gunmen fired on Belgian paratroopers as they escorted a convoy of cars hunting for the last foreigners in the capital, Kigali; the Belgians fired back and managed to pick up more than 40 foreigners, including a dozen Americans, and take them to the airport for an evacuation flight.

* The rebel Rwandan Patriotic Front, dominated by the minority Tutsi people, kept advancing into Kigali, overwhelming the government army, dominated by the majority Hutu people.

* Fearful civilians were scurrying out of the city; a reporter described a stream of people heading out of Kigali as “eight miles long”; Doctors Without Borders, a private French organization, estimated that 150,000 to 200,000 refugees were fleeing central Rwanda in every direction.

* More than 5,000 refugees were cowering in safety in the U.N. compound in Kigali, but their food and water supplies were running low.

Boutros-Ghali, on a tour of European capitals, told the Security Council in a letter that he had been informed of the Belgian decision to withdraw by Belgian Foreign Minister Willy Claes. Ten Belgian soldiers died in Kigali on the first day of rioting when they tried in vain to protect the prime minister, Agathe Uwilingiyimana, a Tutsi, from a murderous band of Hutu soldiers.

The blood bath erupted a week ago when a plane crashed in Kigali, killing Rwandan President Juvenal Habyarimana and Burundian President Cyprian Ntaryamira, both Hutus. The Rwanda government accused rebel Tutsi of shooting down the plane, an accusation that set off Hutu soldiers on an orgy of revenge.

Boutros-Ghali said that he had asked Jacques-Roger Booh Booh of Cameroon, the top U.N. civilian, and Brig. Gen. Romeo Dallaire of Canada, the force commander, “to prepare plans for the withdrawal of (U.N. peacekeepers) should this prove necessary and send their recommendations to me in this regard.”

But Keating’s remarks implied that the Security Council might have to close the operation whatever the Belgians decide because the force could no longer accomplish its original mission.

In Kigali, Reuters correspondent Peter Smerdon reported, “As night fell over the blood-soaked capital, gangs of frightened Hutus, drunk on banana beer, erected more roadblocks across the city and threatened to kill anyone they did not know or recognize, including government soldiers.

“The city was wild with mass hysteria,” Smerdon went on, “the air filled with gun bursts, shrieks and the scent of death. People cowered in fear that the rebels, creeping closer now and veiled by darkness, would kill them.”

All sources reported that the Tutsi-dominated rebels, with a force of perhaps 20,000, appeared to be winning the battle for Kigali.

Meanwhile, the first convoy of aid, nine trucks with 25 tons of medical supplies and two surgical teams, reached Kigali from Burundi. The convoy was organized by Doctors Without Borders and the International Committee of the Red Cross.

In New York, U.N. spokesman Joe Sills said that the U.N. peacekeepers were “making an effort to respond to requests for assistance within the limits of the resources that they have.” He said the peacekeepers were caring for at least 5,000 refugees in the U.N. compound but “supplies are dwindling, particularly foodstuffs and water.”

Ethnic killing has been a hallmark of Rwanda and neighboring Burundi for more than 30 years. For centuries, the Tutsi, a tall Hamitic people who originated in Ethiopia, ruled as lords over the far more numerous and shorter Bantu Hutus.

But this feudal system--with the Tutsi providing cattle, land and protection and Hutus providing labor and their hoes--is disintegrating, and there has been a successive series of ethnic massacres and acts of vengeance that have kept the two small countries in bloody turmoil.