We've heard the allegations that the Darfur rebels are operating out of Chad where they receive covert support from the US. Has Sudan now entered this bloody game by grooming a Chadian rebel force on its own territory?

EL-GENEINA, Sudan, Dec 21 (Reuters) - Chadian rebels opposed to President Idriss Deby said on Wednesday they were poised for a fresh attack against a town on the border with Sudan which they attempted to storm at the weekend.

The rebel Rally for Democracy and Liberty (RDL) said in a statement telephoned to Reuters its forces had made a "tactical withdrawal" from the town of Adre on Chad's eastern border with Sudan after Sunday's fighting.

Chad's government says its army repulsed two attacks by the rebels on Adre, pursued them over the border into Sudan and destroyed their bases there. It accused Sudan of supporting the attackers and said around 300 of them were killed.

Speaking by telephone to a Reuters reporter in el-Geneina, in Sudan's western Darfur region, RDL official Abdullahi Abdel Karim rejected the Chadian government's version of the fighting as contradictory and exaggerated.

"RDL fighters are at the gates of Adre and occupy all the main approaches leading to the town. The next assault will be decisive," Abdel Karim said in what was the rebel group's first known public comment on the fighting.

The RDL spokesman said more than 70 Chadian government troops were killed and about 50 wounded in the battle over Adre.

He put the RDL losses at nine dead and 14 wounded and said 470 government soldiers had been captured.

There has been no independent confirmation of the widely differing casualty figures given by either side.

Hospital patients at el-Geneina, about 30 km (19 miles) from the Chad border, said 25 to 30 fighters injured in the Adre fighting had been brought into the hospital.

But armed soldiers and plain-clothed security men prevented journalists from entering their ward.

The RDL statement said the rebels shot down two government helicopters and destroyed seven tanks and 27 other vehicles. But there was no independent verification of the claim.

The fighting over Adre in Chad has raised tensions in the neighbouring region of Darfur where Sudanese rebels have fought Sudan's central government for almost three years.

INTERNATIONAL CONCERN

Chad has accused Sudanese President Omar Hassan al-Bashir's government of sheltering and equipping armed opponents of Deby "as though they were part of the Sudanese army". It said it will pursue them inside Sudan if necessary.

Scores of Chadian soldiers deserted their barracks in late September before regrouping near the border and joining up with other rebels to attack the government.

Abdel Karim repeated the rebels' demand that Deby should step down.

"Any solution other than the departure of Chadian President Idriss Deby is impossible," he said.

The international community is showing growing concern about the fighting in eastern Chad and in Darfur, a region the size of France where tens of thousands have been killed and more than two million people have been forced to flee their homes.

U.N. Secretary-General Kofi Annan has warned the region is descending into anarchy.

The United States said rebel groups in Chad could launch fresh attacks and warned American citizens about the dangers of travelling there.

The British government issued a similar warning to its nationals.

See our last posts on Chad and Darfur.