Kinshasa - The Lord's Resistance Army (LRA) has killed more than 100,000 people during a reign of terror in Central Africa over the past 25 years.
The guerrilla group led by Joseph Kony, whose global notoriety was increased by the Invisible Children internet video, is also blamed for the abduction of between 60,000 and 100,000 children and the displacement of 2.5 million people.
UN leader Ban ki-Moon said in a report that the office of the high commissioner for human rights, Navi Pillay, had researched the death toll as part of a study on the impact of the LRA since 1987.
Kony, a former church altar boy, originally launched an uprising against the Ugandan government in the 1980s. His group has since staged attacks in several countries.
He is wanted by the International Criminal Court for war crimes and is believed to be hiding in jungles on the border between Sudan, South Sudan, Democratic Republic of Congo and Central African Republic.
But conflict in the region has brought an international hunt for Kony to a near standstill.
While the intensity of the guerrilla attacks has eased, Ban said "suspected LRA attacks continued to be reported in remote border areas" of Central African Republic and DR Congo.
His report said the LRA was blamed in 2012 for about 212 attacks that left 45 dead, while another 220 people were abducted -- a quarter of them children.
The guerrillas are accused of using their hostages as sex slaves and porters.
The UN report said more suspected attacks had been reported in 2013, with additional casualties and abductions, but it did not give a figure.