The European Union is deploying a 3,700-strong EUFOR force to protect civilians and humanitarian operations in eastern Chad and northeastern Central African Republic near the volatile border with Sudan's Darfur region.

Around 200 French soldiers stationed in Birao, a remote town in northeastern CAR which was attacked and briefly occupied by rebels in late 2006, transferred to the force at a ceremony on Saturday, EUFOR's Lieutenant-Colonel Patrick Poulain said.

"They left French command and entered the command of EUFOR," Poulain said on Sunday from the Chadian capital N'Djamena, where the force has its operational headquarters.

The French infantry unit, engineers unit and field hospital will be joined later by other European forces, although the bulk of EUFOR will be based in Chad, he said. The force will have an initial mandate of 12 months, which is expected to begin in the next few weeks when it becomes operational.

The deployment was delayed for several months by problems securing equipment, notably enough helicopters to cover an area 26 times the size of Kosovo with a fraction of the European Union force previously deployed to that conflict zone.

France, which is contributing more than half of EUFOR's troops, formerly ruled both Chad and CAR as colonies and has stepped in to help both governments fight off rebel attacks.

Last month French forces ferried tank ammunition from Libya to Chadian President Idriss Deby's forces as they repelled a rebel attack on Chad's capital N'Djamena, drawing criticism from rebels who accused Paris of "neo-colonialist" intervention.

French special forces helped Central African Republic's army recapture Birao from rebels in late 2006, and has maintained a small military contingent in the town since then.

EUFOR sustained its first fatal casualty last week when two French soldiers strayed across the Sudanese border and came under fire from a Sudanese army position.

A French soldier was killed and the Sudanese government said five civilians were also killed. The incident tested already tense relations between Paris and Khartoum, which Chad accuses of backing last month's rebel assault on N'Djamena -- a charge the Sudanese government denies.

Deby and Sudanese President Omar Hassan al-Bashir are due to sign a peace pact on Wednesday at an Organisation of the Islamic Conference summit in Senegal. A string of previous deals have failed to heal the rift between the neighbours.