A third Chadian rebel faction has engaged in combat with the Chadian army in the east of the country. Other groups have retreated, saying they are preparing new attacks. Meanwhile, humanitarian workers say their work is being complicated because many roads have been blocked following the recent escalation in fighting. VOA's Nico Colombant has more from our regional bureau in Dakar.

Skirmishes broke out between the Assembly of Forces for Change, known by its French acronym RFC, and government forces around the town of Aram Kole.

The violence started despite calls by RFC leaders that they wanted to hold talks with government leaders in the Chadian capital N'Djamena.

Several rebel groups resumed attacks last week after a one-month lull that followed an unfulfilled peace agreement signed in Libya.

A rebel spokesman Makaila Nguebla says the other two rebel groups who have been engaged in fighting were forced to stop offensives last week after Chadian government forces deployed heavy firepower, backed by French military surveillance flights.

But he says many of the rebels are regrouping along the border with Sudan, and the separate rebel factions are trying to team up for a new offensive.

He warns full-scale attacks could begin in the next few days.

During the violence last week, Chad's army was engaged on several fronts. The mainly ethnic Tama rebel group the United Front for Change entered the Tama-dominated area of Guereda last week after government troops pulled out to fight rebels from another group, the United Forces for Democracy and Development, further south.

Many of the rebel groups have splits within their own movements, with some of their members in favor of talks and others all-out violence to topple Chadian President Idriss Deby.

A UFDD leader, Amine Bendarka, says the government needs to show good faith, stop its military operations and resume setting up commissions to discuss power-sharing and disarmament.

Meanwhile, aid workers say they need a return to peace as well, to help the hundreds of thousands of displaced people who have fled fighting in Chad and neighboring Sudan.

Annette Rehrl is a spokeswoman for the U.N. refugee agency. "We hope that the fighting will end soon and that the crisis (will end), and that they will find their way back to dialogue and to peace," she said.

She says fighting and the movements of soldiers and rebels has blocked off access to refugee camps, making it more difficult to reach Chad's internally displaced.

"We are also hindered in getting to the IDPs (internally displaced people), which is always more complicated than getting to refugee camps because the internally displaced Chadians are not living in specific sites. They live in over 200 villages between (the main eastern city of) Abeche and the Sudanese border," she said.

The European Union has been trying to organize a 3,700 member peacekeeping force to deploy in Chad, but has faced logistical and financial delays to deploy.