A policeman walks near tires set aflame by Sudanese protesters marking the first anniversary of a raid on an anti-government sit-in, in the Riyadh district in the east of Khartoum on June 3, 2020. [AFP]

A feared Sudanese militia chief "willingly and enthusiastically" participated in war crimes, the International Criminal Court's chief prosecutor charged Wednesday, laying out searing accusations of rape, murder, and torture.

Prosecutor Karim Khan was summing up in the case of Ali Muhammad Ali Abd-Al-Rahman, also known by the nom de guerre Ali Kushayb, facing 31 charges of war crimes and crimes against humanity during Sudan's brutal civil war.

A leader of Sudan's infamous Janjaweed militia, and ally of deposed Sudanese leader Omar al-Bashir, Abd-Al-Rahman is suspected of brutal attacks on villages in the Wadi Salih area of Darfur in August 2003.

Abd-Al-Rahman, who appeared in court wearing a light suit and striped tie, has denied the charges. He sat impassively as prosecutors presented closing arguments.

He stands accused of war crimes and crimes against humanity including murder, rape, torture, pillaging, and cruel treatment.

"The accused in this case was a senior Janjaweed member, a leader, and was actively involved in the commission of offences, willingly and enthusiastically," Khan told the court.

"The stark reality is the targets in this case were not rebels but civilians. They were targeted. They have suffered. They've lost their lives. They've been scarred physically and emotionally in a myriad of different ways," added the prosecutor.

Fighting broke out in Darfur when non-Arab tribes, complaining of systematic discrimination, took up arms against Bashir's Arab-dominated government.

Khartoum responded by unleashing the Janjaweed, a force drawn from among the region's nomadic tribes.

The United Nations says 300,000 people were killed and 2.5 million displaced in the Darfur conflict.

Khan said that witnesses during the trial had shared testimony of the horrors committed by the Janjaweed.

"They have detailed accounts of mass murder, torture, rape, targeting of civilians, burning and pillaging of entire villages," he said.

He said the militia raped children in front of family members, using sexual violence as a deliberate "policy."

The ICC is holding three days of hearings in the case, the first-ever stemming from a UN Security Council referral.

Bashir, who ruled Sudan with an iron fist for three decades, was deposed and detained in April 2019 following months of protests in Sudan, and is wanted by the ICC for genocide.

He has not been handed over to the ICC, based in The Hague, to face multiple charges of war crimes and crimes against humanity.

Abd-Al-Rahman fled to the Central African Republic in February 2020 when the new Sudanese government announced its intention to cooperate with the ICC's investigation.
Four months later, he surrendered voluntarily.

Prosecutor Khan is also hoping to issue warrants relating to the current situation in Sudan.

Tens of thousands have been killed and millions displaced in a war between the paramilitary Rapid Support Forces (RSF) and Sudan's army.

The conflict, marked by claims of atrocities on all sides, has left the northeast African country on the brink of famine, according to aid agencies.

On Monday, a Sudanese military air strike on a market in North Darfur killed more than 100 people, according to a pro-democracy lawyers' group.

Both sides have been accused of targeting civilians and deliberately shelling residential areas.

The army on Tuesday dismissed the accusations against it as "lies" spread by political parties backing the RSF.

The ICC last year opened a new investigation for war crimes in the region, and Khan said it had made "significant progress".

"I sincerely do believe that this trial represents a step forward in the quest for justice," he told the court, referring to the case against Abd-Al-Rahman.