The U.N. Office for the Coordination of Humanitarian Affairs said that since Dec. 25, the rebels have killed 40 people in the Faradje district, 89 around Doruma and 60 in the Gurba area, and at least 120 houses have been burned down, the Agence France-Presse reported.
The attacks come as DR Congo, Uganda and southern Sudan have launched a military operation to find LRA leader Joseph Kony, who is wanted by a United Nations tribunal to face war crimes charges.
Kony, a former altar boy, took charge of a regional rebellion among northern Uganda's ethnic Acholi minority in 1988. The LRA is accused of having raped and mutilated civilians, and forcibly enlisted child soldiers.
Peace talks between Uganda and the LRA, brokered by the regional government of south Sudan, have stalled. Kony has repeatedly refused to sign a peace deal because of International Criminal Court arrest warrants against him and his lieutenants for war crimes, according to the AFP.
The LRA's presence and continuing military operations have made northeastern Congo "extremely volatile" and much of the region is inaccessible to aid workers, the U.N. office said.
The U.N. report comes amid accusations by the Ugandan army that the rebel group used machetes and clubs to kill at least 45 people in a church in the northeast on Friday.
Ugandan army spokesman Capt. Chris Magezi said, "We have developed a two-pronged approach to stop these senseless killings: We guard civilian settlements while another force pursues the rebels," according to the AFP.
But LRA spokesman David Nyekorach Matsanga told the AFP that the rebels were not behind the attacks.
"Reports about the LRA killing civilians is another propaganda campaign by the Ugandan army," he said.
The rebels appear to be retaliating against civilians for military attacks including a Dec. 14 air bombing of their main camp in Garamba National Park, the Associated Press reported.