A UN human rights mission has confirmed "disturbing" findings about massive abuse of refugees fleeing attacks by government-backed militia and Sudanese troops in Sudan's western Darfur region, a spokesman said Tuesday.

The team probing allegations of ethnic cleansing and widespread atrocities involving hundreds of thousands of people returned to Geneva Monday after spending six days in Darfur, UN human rights spokesman Jose Diaz said.

He declined to reveal their findings, which will be detailed in a report to the UN's top human rights body that is due to be completed at the end of the week.

However, Diaz pointed to the "disturbing nature" of the information the human rights experts had gathered from Sudanese refugees in neighbouring Chad last month.

"Following this latest mission, the team confirmed the assessment it made after its visit to refugee camps in Chad from April 5 to 14," Diaz told journalists.

The United Nations has not made public the findings of the earlier visit to Chad.

But, in a copy of a report on the interviews with refugees in Chad obtained by AFP two weeks ago, the mission concluded that many of the violations in Darfur "may constitute war crimes and/or crimes against humanity".

It also called for an international inquiry into the violence in the western Sudanese region, where Arab militias, known as janjaweed, have been accused of attacking African inhabitants, killing them or forcing them to flee to government-run camps or to neighbouring Chad.

Up to one-million people have been displaced and more than 100 000 of them have sought refuge in Chad, according to the UN.

"The patterns of violence point to an intent on the part of the Sudanese authorities to force the population to disperse," the earlier report said.

It outlined a pattern of air raids followed by ground attacks by militia or soldiers, with indiscriminate killings of civilians, multiple rape, and pillaging.

"It is clear that these attacks fail to distinguish between civilians and combatants and are disproportionate in nature," the unreleased report said.

Sudan's foreign minister has acknowledged that there had been human rights violations in the strife-torn Darfur region, where an estimated 10 000 people have died over the past year.

But Mustafa Ismail denied last month that there was any "ethnic cleansing or collective extermination".

Khartoum allowed the UN team into Sudan on April 22, after barring access for weeks.

The UN mission was able to spend six days in Darfur, meeting displaced people in the three regional capitals as well as outlying areas, Diaz said. - Sapa-AFP