A UN human rights team on Monday accused Sudan's government of "orchestrating and participating" in war crimes in the country's war-torn Darfur region.
The team, led by Nobel peace prize laureate Jody Williams, said Sudan's government "has manifestly failed to protect the population of Darfur from large-scale international crimes, and has itself orchestrated and participated in these crimes."
The report said significant steps have been taken by the international community, including the African Union and the United Nations, but "these have been largely resisted and obstructed, and have proven inadequate and ineffective."
It called for more effective UN Security Council intervention, sanctions and criminal prosecution.
The UN Human Rights Council dispatched the high-level mission to investigate allegations of abuse during an emergency session last December.
Although the team was prevented from visiting Darfur by the Sudanese government, it consulted with aid agencies working in the region and was also briefed by African Union officials in Addis Ababa, Ethiopia, the report said.
The UN team members also met with members of rebel groups in neighbouring Ndjamena, Chad and with Darfur refugees in eastern Chad.
More than 200,000 people have died and more than 2.5 million people displaced in Darfur's four-year conflict.
The conflict erupted in 2003 when members of the region's ethnic African tribes rose up against what they saw as decades of discrimination by the Arab-dominated government in Khartoum.
The government is accused of unleashing a pro-government Arab militia -- known as the janjaweed - who have committed many of the atrocities, including mass rape, abduction, and forcing people from their homes.
Khartoum denies the allegations but members of the janjaweed have said they received arms from the government.
"War crimes and crimes against humanity continue across the region," the 35-page report said. "The principal pattern is one of a violent counterinsurgency campaign waged by the government of the Sudan in concert with janjaweed militia, and targeting mostly civilians. Rebel forces are also guilty of serious abuses of human rights and violations of humanitarian law."
The report also said that rape was widespread throughout Darfur, but that Sudanese authorities weren't making an effort to protect its citizens or to investigate the crimes.
"Arbitrary arrest and detention in Darfur by government security forces continue," the report said, adding that there had been a recent spate of arrests in the nation's capital, Khartoum.
There have also been limitations on free speech and "credible information on torture, inhumane and degrading treatment by national Security and Military Intelligence during attacks and in the treatment of detainees," the report said.
Last month, prosecutors at the International Criminal Court in The Hague, Netherlands linked Sudan's government to war crimes in Darfur.
The court named a junior minister as a war crimes suspect who helped recruit, equip and fund the janjaweed.
Ahmed Muhammed Harun, the former junior interior minister responsible for the western region of Darfur, and a janjaweed militia leader, Ali Mohammed Ali Abd-al-Rahman are suspected of a total of 51 counts of war crimes and crimes against humanity, according to prosecutor Luis Moreno-Ocampo.
Officials have said they do not have to turn over the suspects named by the ICC because they will be tried in Sudan's war crime courts.
