(Adds EU green light for peacekeeping force, paragraphs 5-6)

By Betel Miarom

N'DJAMENA, Oct 15 (Reuters) - Twenty people were killed in ethnic clashes in east Chad after the desertion of former rebels loyal to the defence minister stoked tensions in the region bordering Sudan's Darfur, government sources said on Monday.

The violence between the Tama and Zaghawa communities broke out after an armed group of Tama fighters who had served under Defence Minister Mahamat Nour abandoned the eastern town of Guereda last week and moved close to the Sudanese border. They accused Chad's armed forces of trying to disarm them.

Details of the inter-communal fighting were scarce but it appeared armed Zaghawa clansmen had taken advantage of the absence of Nour's men in Guereda to settle scores with Tamas. Clan rivalries run deep in eastern Chad as in Darfur, many local residents go about armed and clashes are frequent.

News of the latest violence emerged as European Union foreign ministers meeting in Luxembourg approved the planned deployment of an EU peacekeeping force in eastern Chad to protect civilians, refugees and aid workers.

Ex-colonial power France will provide roughly half the U.N.-authorised force of up to 3,000 troops, due to begin its mission within weeks.

Chad's President Idriss Deby flew on Sunday to Biltine, the main town of the eastern Wadi Fira border region, and instructed the local governor to travel to Guereda to calm the situation, the government sources, who asked not to be named, said.

"There are 20 dead and lots of material damage," one said.

The desertion of the group of Nour's men, former members of the rebel United Front for Democratic Change (FUC) which he once led, raised fears of fresh splits inside Chad's fractious armed forces at a time when Deby's government is trying to push through a peace deal with other eastern rebels still under arms.

SHIFTING ALLEGIANCES

It also raised questions about the role of Nour, a Tama and former anti-Deby rebel chief who signed a peace deal with the Zaghawa president in December and was later named defence minister.

Nour has appealed for calm among his Tama fighters and flew back to Chad's western capital N'Djamena on Sunday after receiving treatment abroad for an illness.

He was expected to meet Deby in Biltine later on Monday.

The clashes in east Chad follow a surge in violence over the border in Sudan's Darfur, where rebels, militias and African Union peacekeepers have tangled in clashes ahead of planned Darfur peace talks in Tripoli this month.

The EU force for Chad is deploying to complement an even bigger United Nations/African Union force planned for Darfur, where a local rebellion and ethnic fighting since 2003 have killed some 200,000 people, experts say. Sudan's government rejects this figure, saying the death toll is much lower.

Deby, who has ruled Chad since he took power through an eastern revolt in 1990, has seen his government shaken by splits and military desertions over the past two years.

His government signed a peace deal in Libya last week with four rebel groups. The accord promises the rebels government posts in return for a ceasefire, but some rebel leaders have said differences remain over disarmament.

AlertNet news is provided by