Captured Ugandan Lord's Resistance Army rebel chief Dominic Ongwen will be sent to the International Criminal Court to face charges of war crimes and crimes against humanity, Uganda's military said Tuesday.

Ongwen, who is in custody of US special forces after surrendering in the Central African Republic last week, has been sought by the ICC for almost a decade to face charges including murder, enslavement, inhumane acts and directing attacks against civilians.

"Finally it has been decided, Dominic Ongwen will be tried at the ICC in The Hague," Ugandan army spokesman Paddy Ankunda said, ending speculation that Kampala might seek to put the ex-rebel on trial in its own court.

"Ongwen will be conveyed to The Hague by CAR authorities... in consultation with the relevant bodies," Ankunda said, adding he would be transferred "hopefully very soon," without giving further details.

In Washington, the Pentagon said Ongwen ended up in the custody of US forces after he surrendered to "a third party" claiming to be rebels from the Muslim Seleka movement, spokesman Colonel Steven Warren told reporters.

Asked if the fugitive LRA commander would be handed over to the International Criminal Court, he said: "It's too early now to announce a decision on next steps. We are working through that."

The LRA has been blamed for the slaughter of over 100,000 people, and kidnapping of more than 60,000 children during a three-decade-long campaign across five central African nations.

A former child soldier himself, Ongwen was a senior aide to LRA leader and warlord Joseph Kony.

Ongwen, who is in his mid-30s, is accused of directing bloody campaigns in northern Uganda in the early 2000s, where thousands of people were killed or abducted to be used as child soldiers or sex slaves. Other abductees were deployed to carry out attacks on civilians in the Democratic Republic of Congo.

ICC spokesman Fadi El Abdallah told AFP the court welcomed "all cooperation" that led to wanted suspects being brought to trial.

- Punishment raids -

Known as the "White Ant", Ongwen's troops excelled in punishment raids, which involved slicing off the lips and ears of victims as grim calling cards.

The US State Department accused him of "murder, enslavement and cruel treatment of civilians," and offered a $5 million bounty for information leading to his capture.

Uganda is a signatory to the ICC and is legally bound to hand over wanted suspects to the court.

However, Ugandan President Yoweri Museveni last month called for African nations to quit the ICC, accusing the court of being used as a "tool to target" the continent.

Over 12,000 ex-LRA fighters -- mainly footsoldiers who were themselves abducted by the gunmen -- have been pardoned under a government amnesty designed to encourage those still in the bush to surrender.

But presidential spokeswoman Lindah Nabusayi said Tuesday the amnesty did not cover those accused of crimes against humanity or those wanted by the ICC, saying the president would not "pardon terrorists who have abused the sanctity of human life."

Long driven out of Uganda, small bands of LRA fighters now roam forest regions of CAR, DR Congo, Sudan and South Sudan.

Kony, who claims mystical-religious powers, has reportedly been based in the Sudanese-controlled Kafia Kingi enclave in recent years.

Uganda is leading an African Union mission, backed by US special forces, to hunt down top LRA commanders.

On Monday, Uganda's NTV television station broadcast an audio interview with a man they said was Ongwen, appealing to remaining fighters to surrender.

He said he fled because Kony had wanted to kill him, telling comrades he "only wants to be chief and for you to work for him like a slave".

ICC arrest warrants were issued for five LRA commanders, but after Ongwen's capture and the killing of other movement leaders, only Joseph Kony and Okot Odhiambo remain at large. Uganda has said Odhiambo may also have been killed.