FACTBOX: Chad's rebellion

(Reuters) - Fighting raged for a second day on Sunday around the presidential palace in the Chadian capital N'Djamena, where rebel forces have surrounded President Idriss Deby and loyalist troops, residents said.

Following are details of the rebellion against Deby, who seized power in 1990 with his own uprising launched from his native eastern Chad:

HOSTILITIES

** Chad and Sudan, both oil exporters, trade accusations of hosting rebel groups to undermine the other, though each denies it. Deals brokered mainly by Libya have failed to stop the enmity.

** Dissent over Deby's handling of the dispute led to large-scale army desertions in 2004 and 2005, which prompted him to dissolve his presidential guard and form a new elite force.

** A border attack by deserters in December 2005 signalled an escalation in the rebellion, with an increase in attacks on towns and government forces, mainly in eastern Chad.

** In April 2006, rebels surged right across Chad to reach N'Djamena in the west. Government forces repelled the attack, but hundreds of people are estimated to have been killed.

** Hostilities have ebbed and flowed since. Military campaigns in Chad and Sudan tend to grind to a halt when summer rains fill up dry river beds, cutting off large areas of territory until the water subsides.

** Last year, hundreds were killed in fierce battles between rebels and government in eastern Chad.

** Rebel factions and alliances are constantly shifting, complicating efforts by Deby to co-opt rebel leaders.

BACKGROUND

** Eastern Chad's conflict is tied up with the civil war across the border in Sudan's Darfur region, where Sudanese government forces and allied mounted Janjaweed militias have fought a range of Dafuri rebel factions since early 2003.

** Some 240,000 Sudanese refugees have crossed into Chad, where they live in camps along with 180,000 Chadians displaced by violence in the border area, including raids by Sudanese Janjaweed militia and Chadian groups.

EU DEPLOYMENT

** European Union ministers have given the final green light to a deployment of 3,700 EU peacekeepers to eastern Chad with a U.N. mandate to protect the 420,000 refugees and aid operations.

** The deployment has been delayed because of the rebel advance. France, the former colonial power, which will provide the bulk of the force, has flown reinforcements to its own garrison in Chad.