Soldiers and rebels have both claimed to have killed several hundred of their opponents in combat on Monday in eastern Chad in what may turn out to be the heaviest fighting since rebels tried to take the capital last year.
The battles at Abougouleigne, about 90km east of the town of Abeche, left "several hundred [rebels] dead, several injured and several prisoners of war" taken into military custody, a statement from the army's general staff said.
The rebels issued a similar statement.
"Loss of human life on the enemy side, more than 200 [soldiers] dead, including division General Dirmi Haroun and Colonel Guende Abdramane," said a statement of the Union of the Forces for Development and Democracy posted on a Chadian opposition Web site.
The Chadian army statement did not give any figures of casualties on the army side. But the rebel statement said that only 20 of its combatants were killed and another 41 injured.
Both statements said that these are just preliminary reports on Monday's battles.
It was not possible to independently confirm either side's claims, but if proved true, Monday's fighting would be the worst since a separate rebel group tried to take the capital in April last year.
At the time the government said it killed more than 300 rebels.
Chad has struggled in the face of several rebellions in the east, with some insurgents saying Chadian President Idriss Deby has not provided enough support to their kinsmen in the neighboring Darfur region of Sudan.
Last month, four Chadian rebel groups signed a peace deal in Libya with Deby's government.
However, the Union of Forces for Development and Democracy said last week it was unsatisfied with the pace of implementing the agreements, and then its fighters clashed with government forces over the weekend.
No information was immediately available about casualties from the weekend clashes.
UN officials estimate that around 3 million people have been uprooted by conflicts in the region, also including the fighting in Darfur and unrelated rebellions in Chad and Central African Republic.