Five African heads of state met Monday in Arusha, Tanzania, to prepare for the launch of a transitional government aimed at ending Burundi's years of civil war. The leaders have just four weeks to set up a special security force to protect returning political exiles.

The Arusha summit is the last one before Burundi's current president, Pierre Buyoya, is sworn in as leader of the country's transitional government on November 1. That means the leaders of Burundi, Tanzania, Uganda, Kenya and Rwanda, joined by former South African President Nelson Mandela, have a lot to do in a little time.

The most urgent task is the setting up of a special protection unit of some 1,000 soldiers to provide security for politicians who are returning to Burundi after years of civil war.

In the last eight years, some 200,000 Burundians, mostly civilians, have been killed in fighting between the Tutsi-dominated army and government and Hutu rebels.

Most of the returning politicians are from the majority Hutu community, and Hutu representatives at the talks want the protection force to be made up of foreign soldiers. But President Buyoya, a Tutsi, wants to use soldiers from the mainly Tutsi Burundian army.

Mr. Buyoya is an ex-soldier who took power in a coup in 1996. According to the peace plan, he is due to hand over power to a Hutu president in 18 months. After another 18 months, there will be democratic elections, Burundi's first since the war began in 1993.

This gives the negotiators three years to persuade the Hutu rebels to lay down their arms. The rebels have refused to take part in the Arusha peace process or to agree to a cease-fire and fighting has intensified this year.

But they have started holding separate talks in South Africa, home to chief mediator Nelson Mandela.

The Arusha accord also envisages an international peacekeeping force for Burundi. South Africa, Senegal, Nigeria and Ghana have offered to send troops, while Belgium has promised logistical support.