Sudan has rejected a call by U.N. experts for the deployment of an "independent and impartial force" to protect millions of civilians driven from their homes by more than a year of war.

The conflict since April last year, pitting the army against paramilitary forces, has killed tens of thousands of people and triggered one of the world's worst humanitarian crises.

The independent U.N. experts said Friday their fact-finding mission had uncovered "harrowing" violations by both sides, "which may amount to war crimes and crimes against humanity."

They called for "an independent and impartial force with a mandate to safeguard civilians" to be deployed "without delay."

The Sudanese foreign ministry, which is loyal to the army under General Abdel Fattah al-Burhan, said in a statement late Saturday that "the Sudanese government rejects in their entirety the recommendations of the UN mission."

It called the UN Human Rights Council, which created the fact-finding mission last year, "a political and illegal body", and the panel's recommendations "a flagrant violation of their mandate."

The UN experts said eight million civilians have been displaced and another two million people have fled to neighboring countries.

More than 25 million people upwards of half the country's population — face acute food shortages.

World Health Organization chief Tedros Adhanom Ghebreyesus, on a visit to Sudan on Sunday, said: "The scale of the emergency is shocking, as is the insufficient action being taken to curtail the conflict and respond to the suffering it is causing."

In Port Sudan, where government offices and the United Nations have relocated to due to the intense fighting in the capital Khartoum, Tedros called on the "world to wake up and help Sudan out of the nightmare it is living through".

The Sudanese foreign ministry statement accused the paramilitary Rapid Support Forces, led by Burhan's former deputy Mohamed Hamdan Daglo, of "systematically targeting civilians and civilian institutions".

"The protection of civilians remains an absolute priority for the Sudanese government," it said.

The statement added that the UN Human Rights Council's role should be "to support the national process, rather than seek to impose a different exterior mechanism".

It also rejected the experts' call for an arms embargo.