NDJAMENA, April 1, 2008 (AFP) - Fighting broke out between rebel and government forces in eastern Chad on Tuesday, nearly two months after a failed insurgent bid to oust President Idriss Deby Itno, rebel officials told AFP.

The clashes occurred in the eastern Ade region bordering Sudan, said Ali Gadaye, spokesman for the main rebel group, the National Alliance.

A statement from Chad's defence ministry, confirming the fighting, said the rebel attack had been ordered by Sudan and violated a recent peace accord signed between the two neighbours.

The statement said that at 6.40 a.m. (0450 GMT) 'mercenaries (rebels) crossed the border on the orders of the Sudanese regime to attack the Ade district.'

'Government forces pushed back the the enemy, who are in full flight.'

But a second rebel official said army forces had instigated the fighting. 'We counter-attacked and are now in control of Ade,' he said by satellite phone from the region.

The defence ministry statement called on Congo, Libya and Senegal, who sponsored last month's peace deal between the two countries, to 'assume their responsibilities to stop any aggression that could have unpredictable consequences.'

On March 13, Chad's Deby and Sudan's President Omar al-Beshir signed a non-aggression pact, vowing not to support rebel attacks against each other.

The accord, the sixth such agreement they had signed in five years, came only after intense international pressure.

Over the weekend of February 2-3, an alliance of three rebel groups attacked Ndjamena and got as far as the gates of the presidential palace before being driven back by Deby's troops with indirect French military support.