Two Chadian rebel groups signed an agreement Monday to combine their forces to continue fighting government troops. The announcement comes one day after President Idriss Deby agreed to a peace deal with a leader of another rebel faction. Some members of Chad's fragmented rebel movement are dismissing the accord saying negotiations cannot be made with Chad's government. Kari Barber reports from our regional bureau in Dakar.

Chad's President Idriss Deby (R) shakes hands with rebel leader of the United Front for Change (FUC) Mahamat Nour Abdulkerim (L) in Libya, 24 Dec 2006

Chad's president Idriss Deby signed a peace accord with rebel faction leader Mahamat Nour in Libya on Sunday.

Nour's forces raided the capital, N'Djamena, in April. The deal calls for them to be integrated into the national army.

The government and the rebel groups involved in the accord say they will end military and media campaigns against each other. They say they will also release each other's prisoners and grant amnesty to fighters on both sides.

Members of other rebel groups have rejected calls to join the agreement.

Makaila Nguebla, a Dakar-based spokesman for a rebel group known as the UFDD, says he is not interested in dealing with Mr. Deby's government because he does not consider it legitimate.

He says any negotiations with Mr. Deby should involve international groups such as the United Nations and the African Union.

Chadian troops patrol deployed after the fighting with UFDD rebels in Biltine, 11 Dec 2006

On Monday two rebel groups known as the UFDD and the RAFD formed a coalition to unite their forces under a central command. The two groups have stepped up their attacks on government troops in recent months. Rebels say they have taken up arms because there is no room for political opposition.

President Deby came to power in 1990 as part of a rebel movement. He was later elected in polls that were widely viewed as rigged.

Chad has accused Sudan of backing the rebels, a charge officials in Khartoum have denied.