Dominic Ongwen sits in the court room to listen to the judgment of the Appeals Chamber of the International Criminal Court on the Defence's appeals against his conviction and sentence in The Hague, Netherlands, Thursday, Dec. 15, 2022. [AP Photo]

International Criminal Court appeals judges Thursday rejected the appeal by a former commander in the brutal Ugandan rebel group Lord's Resistance Army of his conviction on dozens of charges of war crimes and crimes against humanity and upheld his 25-year sentence.

In a landmark judgment nearly two years ago, Dominic Ongwen was convicted of 61 offences that included murders, rapes, forced marriages and recruiting child soldiers in 2002-2005.

His lawyers unsuccessfully raised 90 grounds for the appeal, alleging legal, procedural and factual errors in the conviction and sentence.

"The appeals chamber rejects all the defence's grounds of appeal and confirms unanimously the conviction decision," Presiding Judge Luz del Carmen Ibanez Carranza said as Ongwen listened intently through a headset.

In a majority ruling, the five-judge appeals panel also upheld his sentence. Ibanez Carranza issued a partially dissenting opinion, saying she would have asked trial judges to reconsider Ongwen's sentence in part because she believed they wrongly calculated the number of his victims and partially to acknowledge his status as a victim.

Ongwen was himself abducted by the shadowy militia as a 9-year-old boy and transformed into a ruthless child soldier. At trial, his defence lawyers said his abduction and indoctrination in the LRA made Ongwen a "victim and not a victim and perpetrator at the same time."

Ibanez Carranza said in her dissenting opinion that the issue could have been addressed with a new sentence for Ongwen that could "acknowledge his victim status and reinstate the dignity that was taken away from him when he was only a defenceless child." However, because she was in the minority, the sentence remained unchanged.

The appeals chamber rejected arguments that he was mentally unfit to be convicted and that he was under duress at the time of his offences.

The Lord's Resistance Army was formed by its leader, Joseph Kony, as an anti-government rebel force in Uganda. It was accused of widespread atrocities, including mass killings, mutilations, recruiting and using child soldiers, and keeping girls as sex slaves.

A military campaign forced the LRA out of Uganda in 2005, scattering its members across central Africa. Reports over the years have claimed that Kony was hiding in Sudan's Darfur region or in a remote corner of the Central African Republic, where LRA fighters continued to kill and abduct people during occasional village raids, and where Ongwen was arrested in 2015.

Kony, who is a fugitive from the International Criminal Court, became internationally notorious in 2012 when the U.S.-based advocacy group Invisible Children made a viral video highlighting the LRA's crimes.