A Congolese former militia warlord, Thomas Lubanga, has been set free after serving a landmark 14-year term for war crimes handed down by the International Criminal Court (ICC).

Lubanga was greeted by about 100 supporters on his release from a jail in Kinshasa on Sunday, an AFP journalist saw.

In 2006, he was the first person to be arrested under a warrant from the ICC in The Hague, where he went on trial in 2009, accused of enlisting child soldiers under 15.

Lubanga was sentenced to 14 years behind bars in 2012 and has served the full term.

In December 2015, he was transferred from the ICC prison to Kinshasa to serve out the rest of his sentence with fellow Congolese warlord Germain Katanga, who was also convicted by the ICC.

His release comes at a time of unrest in his native region of Ituri, in the Democratic Republic of Congo's volatile east.

Lubanga was hailed by activists from his Union of Congolese Patriots (UPC) party.

One of his lawyers, Papy Mayamba, said the ICC had used him as a "guinea pig".

The militia chief headed the ethnic Hema community of herders and traders in clashes with Lendu people, mainly settled farmers. From 1999 to 2003, tens of thousands of people were killed.

The fighting overlapped with the Second Congo War of 1998-2003, a conflagration that brought more than half a dozen foreign armies on to the country's mineral-rich soil on rival sides.

More than 700 civilians, mostly Hema, have been killed in Ituri since 2017.

Some UN officials have characterised these killings as a possible crime against humanity, blamed on an extremist militia, the Cooperative for the Development of the Congo (Codeco).

Government soldiers on Saturday said they had killed several militia members, including an aide to the Codeco chief.

Local sources said at least five civilians were killed on Friday, part of a total of several dozen in the territory of Djugu.

Displaced people continued Saturday to converge on a camp at Bunia, the chief town of the area. Some women reported being raped by militiamen, while a priest said he lost three of his fingers in a machete attack.