A man accused of leading Sudan's feared Janjaweed militia pleaded not guilty to dozens of war crimes charges on Tuesday, at the start of the International Criminal Court's first trial over the Darfur conflict.

Ali Muhammad Ali Abd-Al-Rahman is charged with overseeing thousands of pro-government Janjaweed fighters during the peak of fighting from 2003-2004 and being responsible for atrocities including murder, rape, pillaging and torture.

“I am innocent of all of these charges,” the septuagenarian told judges after the charges were read out at the start of his case.

Abd-Al-Rahman voluntarily surrendered to The Hague-based court in June 2020.

He has regularly denied the charges and his lawyers have argued in earlier stages of the proceedings he was not the janjaweed militia leader also known as Ali Kushayb.

ICC prosecutor Karim Khan said the trial was a momentous day for those in Sudan who had been waiting for justice for nearly two decades, likening their wait to a fast.

Referencing the Muslim fasting month of Ramadan, Khan said the trial was “an Iftar (breaking of the fast) of sorts for the millions of Sudanese throughout the world that have been yearning for this day to come.”

The trial comes amid what humanitarian groups say is an upsurge of intercommunal violence in Darfur since the end of the United Nations and African Union peacekeeping mission there.

Decades after the worst of the fighting, 1.6 million people are still internally displaced in Darfur, the United Nations estimates.

Darfur's conflict first erupted when mostly non-Arab rebels took up arms against Sudan's government, accusing it of marginalising the remote western territory.

Sudan's then government mobilised mostly Arab militias, known as the Janjaweed, to crush the revolt, unleashing a wave of violence that Washington and some activists said amounted to genocide.

Abd-Al-Rahman has been accused of 31 counts of war crimes and crimes against humanity and could face up to life imprisonment if convicted.

Prosecutors say he was a key Janjaweed leader that the government of Sudan relied upon and who participated knowingly and willingly in crimes.

They dismissed earlier statements by Abd-Al-Rahman that he is not Ali Kushayb.

“Witness after witness saw him, heard him, recognised him. Witness after witness knew Mr Abd-Al-Rahman from before. This is — the prosecution says — a strong case,” Khan said.