The African Union is considering sending 6 000 to 7 000 troops to eastern Congo to forcefully disarm Rwandan rebels linked to the country's 1994 genocide - but the organisation still has to work out key details for the operation, an official said on Wednesday.

Experts will hold meetings later this month to flesh out details of the mission and whether the force will operate on its own, with United Nations troops are already in Congo or with Congolese forces, said Peace and Security Commissioner Said Djinnit.

The presence of Rwandan rebels in eastern Congo has fuelled years of warfare in the vast Central African nation.

The rebels, who include members of the former army and extremist Interahamwe militia from Rwanda's Hutu majority, fled to Congo after leading the genocide of at least 500 000 minority Tutsis and politically moderate Hutus. They then attempted to invade Rwanda in a bid to regain power.

Rwanda has invaded Congo twice in the last decade. A total of 13 775 UN peacekeepers are also deployed in Congo, mainly in provinces bordering Rwanda, to improve security.

"These groups live in mountainous areas and forests and it is very difficult to access. Issues we will need to look at include air support" for the African force, Djinnit said.

He was speaking to reporters at the end of a two-day meeting attended by representatives of the UN mission in Congo, the UN refugee agency, the European Union and officials from Rwanda, Congo and Burundi.

The crisis is the worst humanitarian situation in the world, overtaking Sudan's troubled Darfur region, the UN's humanitarian chief said on Wednesday.

Killings continue unabated in the east of the African country, despite the official end of hostilities over two years ago, said Jan Egeland, head of UN Office for the Co-ordination of Humanitarian Affairs.

"Measured in human lives lost, I think that Congo is the number one problem in the world today," Egeland told reporters, adding that the number of casualties amounts to "a tsunami every month, year in and year out, for the last six years".

About three million Congolese are now in acute need of assistance, Egeland said.

Congo's five-year, six-nation war killed nearly four million people, according to aid groups. The war ended in 2002 with the formation of a transitional government that has struggled to extend its authority to the long-ungoverned east, where violence continue.

Both Congo's President Joseph Kabila and Rwanda's President Paul Kagame have agreed to allow the African Union to coordinate any new operation involving African Union troops to help restore order in the region