PARIS - A French court will decide how six charity workers are to serve sentences meted out to them in Chad, now that the group is back in France.

Officials say the six were jailed shortly after their arrival Friday night at a Paris-area airport.

A court in Chad sentenced them to eight years' forced labour for trying to kidnap 103 children from the African country.

The six -- from the charity group Zoe's Ark -- were transferred to France under a 1976 judicial accord between the two countries.

Because France does not have forced labour, the French justice system will adapt their sentences.

The six are to appear before court in a Paris suburb on Jan. 14.

A state prosecutor says the court will not retry the case but "simply adapt the sentences to French penal code.''

French officials say that under the judicial accord, Chadian officials must agree to the terms of any sentencing changes.

The six aid workers, who launched a hunger strike earlier this month to draw attention to their case, appeared weak and tired when they arrived at Le Bourget airport.

Their transfer to France had sparked protests in Chad, a former French colony in central Africa, with many Chadians decrying what they saw as special treatment for Europeans.

In October, Chadian authorities stopped the aid group's convoy with the children, whom the charity was planning to fly to France. The group's members insisted they were driven by compassion to help orphans in Sudan's conflict-wracked Darfur region, which borders Chad.

But investigations showed most of the children had at least one parent or close adult relative.

The case has been a major embarrassment for France, coming as the country is pushing to send a European Union force to Chad to protect refugees fleeing violence in Darfur.

The deployment of the approximate 4,300-member force, drawn largely from France, already has been delayed because of lack of necessary equipment.

France's Defence Ministry said in a statement Friday that Defence Minister Herve Morin will travel to Chad on Sunday and then to neighbouring Central African Republic to visit French troops stationed there. The European Union force will also top Morin's agenda during the three-day trip, Defence Ministry officials said.