Darfur rebel leader Saleh Jerbo, charged with war crimes by the International Criminal Court, has been killed in the western Sudanese region, his defence team said.

"The defence of Mr Saleh Mohammed Jerbo Jamus hereby notifies the trial chamber, with great sadness... that Mr Jerbo died in North Darfur, Sudan on the afternoon of 19 April 2013, and was buried the same day," said an ICC document published late Tuesday. Jerbo, along with fellow Darfur rebel leader Abdallah Banda, faced three war crimes charges for allegedly leading an attack on African Union peacekeepers in northern Darfur in September 2007, killing 12. The two had been due to go on trial at The Hague-based ICC in May 2014.

"Mr Jerbo was killed during an attack on his location by forces of the Justice and Equality Movement faction led by Gibril Ibrahim," said the ICC document, seen by AFP on Wednesday.

Last Friday Ibrahim's group, the main JEM group, announced it had clashed around Jebel Darma in North Darfur state with a breakaway faction led by Mohamed Bashar, to which Jerbo reportedly belonged. The statement gave no information about casualties.

Bashar's faction signed a peace deal with Khartoum in early April. It became only the second group to join the 2011 peace pact signed in the Gulf state of Qatar between Sudan's government and the Liberation and Justice Movement, an alliance of rebel splinter factions.

Jerbo's lawyers called on the ICC to verify the death. Rebels have been fighting for 10 years in Sudan's far-western Darfur. While the worst of the violence has long passed, instability has been complicated by inter-Arab fighting, kidnappings, carjackings and other crimes, many suspected to be the work of government-linked militia and paramilitary groups.