Chadian leader General Mahamat Idriss Deby Itno on Friday promised to free a dozen men accused last December of trying to mount a coup.

"I hereby commit myself, before you and God, to free compatriots who have been charged for their involvement in the attempted coup d'etat last December," Deby said in a speech to mark the Muslim holiday of Eid al-Fitr.

Deby took the helm of a military junta in April 2021 at the age of 37 after the death of his father, veteran ruler Idriss Deby Itno, and appointed himself transitional president.

He initially promised to hold elections and restore civilian rule within 18 months but then postponed this for another two years, sparking protests in October 2022 that were bloodily repressed.

On January 5, the authorities said that on December 8, they had arrested 11 army officers and a prominent rights campaigner, Baradine Berdei Targuio, whom they accused of "attempting to destabilise... the constitutional order" and the country's institutions.

Berdei Targuio, presented by the authorities as the ringleader, is president of the Chadian Organisation for the Defence of Human Rights (OTDH) and a fierce critic of the two Debys.

The government has given no indications about the state of the case against the 12 since the initial announcement.

Deby, in his speech, likewise gave no further details, and no governing official could be reached on Friday for a response.

Deby's father, who had ruled the vast Sahel country for three decades, was killed during an operation to fight rebels in the north.

His death was announced just a day after he had been declared victor of a presidential election that gave him a sixth term in office.

Last month, the younger Deby pardoned and then freed 259 young people who had been handed jail terms for taking part in the October 22 protests in the capital N'Djamena.

According to the government, 73 people were killed, but the opposition, as well as local and international NGOs delving into accounts of forced disappearances, arbitrary arrests and executions, say the toll is much higher.

In his speech on Friday, Deby announced that other people who had been detained in the provinces during the October 20 protests would now be freed. He did not give a figure.