The United Nations Security Council has authorised a 5,500-strong UN force to monitor the ceasefire in the Democratic Republic of Congo.

The council voted unanimously to increase the UN presence in Congo from its current strength of 90 liaison officers.

The force will comprise up to 500 military observers and up to 5,000 soldiers to provide protection and logistical support.

But the deployment of the force will not begin until UN Secretary-General Kofi Annan is satisfied it will have adequate security and the co-operation of the warring parties.

Diplomats at the UN have voiced concern that the size of the force will be inadequate for a vast country with notoriously poor communications.

But it is hoped that this agreement will create a framework for the international community to help resolve a conflict that's been described as Africa's First World War.

This could be the precursor to a full-blown peacekeeping operation involving as many as 20,000 troops.

That, however, is likely to happen only if there is significant progress towards peace in Congo.

The vote came after the council heard briefings from experts on Congo.

It followed a meeting in the Zambian capital, Lusaka, involving eight African heads of state and the leaders of two of the rebel factions, which addressed some of the UN's concerns over the deployment of a force in DR Congo.

Assurances

Delegates in Lusaka gave the UN the assurances it was seeking on the security of its personnel in the Congo.

They also indicated that they would be willing to agree on a joint command structure, shared between the UN and a military council made up of all the warring parties.

Presidents Frederick Chiluba of Zambia, Laurent Kabila of DR Congo, Pasteur Bizimungu of Rwanda, Sam Nujoma of Namibia, Joaquim Chissano of Mozambique, Jose Eduardo dos Santos of Angola, Zimbabwe's Robert Mugabe and Yoweri Museveni of Uganda attended the recent Lusaka talks, together with senior officials from the UN and the Organisation of African Unity (OAU).

The conflict has drawn in Zimbabwe, Angola and Namibia on the Congolese government side, while Rwanda and Uganda back splintered rebel factions.

A peace accord signed in Lusaka in August has often seemed close to collapse, amid ceasefire violations on both sides.

The United States has voiced its support for the UN force in DR Congo, but has not offered to send any of its troops.