N'DJAMENA - Chad's government will push ahead with a peace process with eastern rebels despite a clash with rebel fighters near the Sudan border that killed one soldier and a dozen insurgents, senior officials said on Friday.

Armed forces chief Gen. Daoud Soumaine said government troops clashed on Thursday at Goz Beida with fighters of the former rebel group FUC (United Front for Democratic Change), which was once led by Chad's current defence minister.

The clash appeared to herald renewed warfare on Chad's eastern border with Sudan's conflict-torn Darfur region after several months of relative calm during the annual rainy season.

Chad's government declared a state of emergency in the east this week after ethnic violence killed at least 20 people.

Soumaine said in the Goz Beida clash, one soldier was killed and three wounded. He put rebel casualties at a dozen dead and six wounded and said the remaining insurgents fled in their vehicles over the border into Sudan.

There was no independent confirmation of the casualties.

"The situation is under control," Soumaine said.

President Idriss Deby's government announced this month it had initialled a preliminary peace deal in Libya with four Chadian rebel groups which had been waging a hit-and-run guerrilla war against Deby's forces in the east. Last year, the end of the rainy season led to a flurry of rebel attacks.

Communication Minister Hourmadji Moussa Doumgor said the government would not be deterred from concluding the peace deal, which foresees disarmament of the rebels and their integration into the national army.

"The government expects to finalise the peace accord," Doumgor said.

The Goz Beida fighting broke out just weeks before the European Union was due to deploy a United Nations-authorised peacekeeping force of up to 3,000 troops in eastern Chad.

Goz Beida lies near several U.N.-run camps housing Sudanese refugees from Darfur and displaced Chadian civilians, but relief workers said these were not hit by Thursday's fighting.

Former FUC fighters had deserted their positions last week at the northeastern town of Guereda. Mostly members of the Tama community, they accused the army and its Zaghawa clan militia allies of trying to disarm them and of attacking civilian Tamas.

Defence Minister Mahamat Nour had once led the FUC group against Deby but signed a peace deal with the Zaghawa president in December and joined the government in March.

He called on Friday for the insurgent ex-FUC fighters to lay down their arms. "All individuals who have not rejoined the (Chadian national) defence and security forces will be considered deserters," Nour said.