Chad has demanded that neighbouring Sudan disarm Chadian rebels in its violent Darfur region as a condition for peace talks to end a growing dispute with Khartoum over rebel and militia raids in the border area. Chad accuses Sudan of sheltering and backing Chadian rebels who attacked the border town of Adre last month. It has declared a "state of belligerence" with Khartoum. The dispute is adding to insecurity in the Darfur region, where local militias backed by Khartoum have been raiding villages, occasionally straying over the border into Chad.In recent months, scores of soldiers have deserted the army in Chad, Africa's newest oil producer, to join rebel groups near the large, arid country's eastern border with Sudan. Khartoum denies backing Chadian rebels but the dispute has cast a shadow over its preparations to host an African Union summit from 23-24 January which Chad says should be held elsewhere. Muammar Gaddafi, Libya's leader, offered to mediate and Chad said Idriss Deby, its president, met Gaddafi in Tripoli at the weekend and laid down four conditions to end the dispute.