Six Chadian opposition leaders, including the co-ordinator for the main opposition coalition Wakit Tamma, have been handed one-year suspended sentences for disturbing public order.
They were also fined 10m CFA francs ($16,000; £12,800). The public prosecutor had requested two years in prison, a fine of 100,000 CFA francs, plus 2bn CFA francs in damages.
The case came after an authorised march they had organised on 14 May against France’s military presence in Chad turned violent.
In the aftermath, the authorities carried out a string of arrests among the march organisers, who denied any responsibility for the violence.
Their trial opened on Monday morning at a court at Moussoro, around 290km (180 miles) from the capital N’Djamena, with defence lawyers boycotting the hearing amid a heavy police presence.
The activists had earlier refused to leave custody to attend the hearing.
Their lawyers said they intend to appeal the sentence at the Court of Appeal in the capital, describing the trial as unfair.
The case comes against a backdrop of political tension with a military junta in power, following the death of the country’s veteran leader Idriss Déby more than a year ago.
