Chad's army has been setting up defensive positions outside the capital N'Djamena as well as about 200 kilometers east to block a new allied rebel offensive.  VOA's Nico Colombant reports from our regional bureau in Dakar.

Chadian military officials say long-time President Idriss Deby is going to the front to block the latest rebel advance, made up of fighters from several rebel groups.

Chadian National Concord (CNT) rebel movement fighters are pictured 11 Dec 2007 in Abougoudam, Chad

Officials say about two rebel columns, each with about 1,000 fighters, are about 200 kilometers east of the capital, near Lake Fitri, traveling in several hundred pick-up trucks.

Meanwhile, the military has set up roadblocks at key intersections in the capital, where most schools were closed, and many civilians rushed home from work.

An exiled rebel spokesman, Makaila Nguebla, tells VOA the rebels are not afraid of Chad's army, and he predicts rebel fighters will make it to the capital.

Nguebla says it is no longer a national army, but a clan-based fighting group with low morale.  He says Mr. Deby must accept political dialogue, or face continuous rebel assaults.

Nguebla does express concern about possible French logistical help for Chad's army.

The former colonial power has a defense treaty with Chad that includes support from French troops permanently based in Chad.

Nguebla says it is now a question of life or death.

French troops in N'Djamena, Chad, 31 Dec 2007

Meanwhile, 3,700 European peacekeepers are deploying in the country as well as the Central African Republic to secure people displaced by various regional conflicts. 

Nguebla says the rebels have no choice but to resume fighting before that force is fully operational.

The European Commander-in-chief General Pat Nash says the peacekeepers have nothing to do with the Chadian conflict, but warns that if targeted, they will shoot back.

The previous major rebel assault on Chad's capital in April 2006 was repelled with French military assistance, mostly aerial surveillance.

President Idriss Deby (file photo)

One month later, Mr. Deby won elections widely viewed as fraudulent.  Sporadic rebel offensives as well as military and political defections from his circle of power intensified after his disputed re-election.

Mr. Deby first took power in a coup in 1990 and later changed the constitution to allow unlimited terms.

Paul Hendy, an analyst for the South African-based Institute for Security Studies, says he is not surprised by this latest rebel activity.  He says the international community must help not just with peacekeepers and securing displaced people, but also with aggressive peace brokering.

"There is no way to express political divergences in Chad except when you bear a weapon," he explained.  "Long-term political solutions should also take into account political change and even change of regime, which this country will certainly need after 17 years of Deby's rule."

Mr. Deby accuses Sudanese authorities of backing the Chadian rebels, who often retreat to bases within Sudan.  Sudan's government denies this, and accuses Chad of backing the major Sudanese rebel groups who are operating in the warring Darfur region.  Many of these groups have their political headquarters in N'Djamena.