The U.N. on Monday accused the Ugandan-based Lord's Resistance Army of killing, mutilating and raping villagers in Sudan and Congo in what may have been crimes against humanity.
The rebels killed at least 1,200 people and abducted 1,400, including children and women, in northeastern Congo from September 2008 to June 2009, said a report by the U.N. High Commissioner for Human Rights.
A separate report by the U.N.'s rights office said that, in at least 27 attacks on villages in southern Sudan, the Lord's Resistance Army killed more than 80 civilians and kidnapped many others to use as child soldiers, sex slaves and spies.
The report called the attacks in Sudan, which it said took place between December 2008 and March 2009, deliberate and brutal.
Both reports were based on hundreds of interviews with survivors and several field trips to the remote areas by U.N. employees, said Rupert Colville, spokesman for the high commissioner.
One survivor in Sudan told U.N. employees that he found the mutilated body of a fellow villager.
"The villager's leg had been chopped off, his jaws had been dislocated and his teeth had been pulled out," the report said.
The rebels frequently cross into Congo and Sudan and are notorious for mutilating and murdering civilians and kidnapping children to use as fighters.
Survivors in Sudan told U.N. investigators that armed Lord's Resistance Army rebels arrived in groups of between five and 20, and attacked people with axes, bayonets, hoes, knives and machetes. They reserved the use of firearms for those who tried to flee, the report said.
The LRA attacks in Sudan may amount to crimes against humanity, while the widespread abuses in Congo may have been war crimes as well, it said.
A spokesman for the rebel group, David Matsanga, denied the allegations in the U.N. reports and called it false and malicious. He said that most of the civilian deaths were caused by the Uganda People's Defense Force, of UPDF, the government's army.
"On many occasions the UPDF and troops from southern Sudan and Congo killed civilians thinking that they were the LRA rebels they were hunting for," he told The Associated Press. "We should not be held responsible for killings made by UPDF and other forces."
Matsanga said the group is tired of fighting and looking for lasting peace.
But, a Sudanese woman who escaped after being abducted by LRA rebels said female captives were regularly mistreated and raped.
"At night the fighters used to tie the abducted men one to another, make them lie on the ground and cover them with a plastic sheet," she was quoted as saying in the report. "They would then take all the women to the bush and rape us. They barely gave us any food and would beat us on a regular basis with sticks, the butts of the guns and their fists."
The report on Congo said thousands of homes, dozens of shops, hospitals, churches and at least 30 schools were looted and set on fire in various parts of Orientale Province. Villagers were mutilated, tortured and raped, the report said.
The LRA has been fighting the Ugandan government for over 20 years, accusing it of discriminating against the country's northern tribes.
The Ugandan military, along with forces from Congo and southern Sudan, launched a joint operation against LRA rebels in Congo from December 2008 to March 2009. The offensive came after rebel leader Joseph Kony failed to turn up last year to sign a peace agreement.
Kony and other top LRA members are accused by the International Criminal Court in The Hague, Netherlands, of war crimes and crimes against humanity. Kony is still at large, as are many of his commanders, although the rebels have splintered into several smaller groups.
The U.N. urged the Congolese government and the international community to step up efforts to arrest Kony and other rebel leaders. Kony is believed to be hiding in Garamba Park _ a vast area in northeastern Congo near the Sudanese border that is covered with thick forest and difficult to access, said Elisabeth Da Costa, an expert on Congo with the U.N. rights office.
In some attacks, the Congolese army helped the LRA, the report said, adding that the country's security forces terrorized some of those who fled.
People faced "harassment, extortion, rape and summary executions committed by the Congolese security forces," the report said.
Associated Press reporter Godfrey Olukya in Kampala, Uganda, contributed to this report.