Human rights groups in Chad are to stage a protest to demand the release of some 20 people who disappeared after being arrested by police a year ago.
Authorities said they captured rebels in the last year's attack
The men were rounded up by security forces after a failed rebel attack on Chad's capital, N'Djamena, last April.
The coalition of rebel groups has since been dissolved.
However, human rights activists say the government has not revealed any information about those arrested despite repeated promises to do so.
Chadian non-governmental organisation, Human Rights Without Borders, says the government must now come clean.
"We've repeatedly asked the government to stick to its word and free these people. Many people have been arrested, and their families have been abandoned. There is no worse violation than a disappearance."
Hadija has not seen her husband since he left for work as usual, one morning a year ago.
"We have no idea where they are. We don't even know if they alive, dead, in prison, in Chad, in another country," she says.
"There is no information, there is no trace. We are in a situation without an end. All night you don't sleep. You are awake, wondering: Are they alive? Are they dead? Are they alive? Are they dead?"
Col Khamis Doukoune, who used to be a senior figure in the Chadian army, vanished on the eve of the rebel attack on N'Djamena.
His nephew, Mahamat Bichara, says his family were devastated.
"When we wake up every day we hope and pray to see him. It's hard to describe to you how hard it is, that he disappeared from one day to the next," he says.
"It's not a legitimate government which kidnaps someone and then refuses to tell the family where they are, or what they've done with them."