premise: The latest incident in El-Fasher, the capital of North Darfur state and the main base for AU troops, came a week after five people were killed in fighting between SLM former rebels and pro-government forces.
  SLM chief Minni Minnawi threatened to quit the government over what he said were repeated attacks by the Janjaweed militia abetted by the regime of President Omar al-Beshir.
  The UN Security Council in August adopted a resolution calling for the deployment of 20,000 UN peacekeepers in Darfur, but Beshir has so far rejected such an option as well as proposals for a "hybrid" AU-UN force.
  Natsios arrived in Khartoum on Saturday in a bid to soften Khartoum's stance on peacekeepers and met Foreign Minister Lam Akol on Sunday.
  "Natsios came with the idea that Sudan had a uncompromising stance and hadn't accepted everything that was decided in Abuja," foreign ministry spokesman Ali Sadek told reporters after the meeting.
   Why did Natsios arrive in Khartoum?
hypothesis: deployment of 20,000 UN peacekeepers in Darfur