The threats are reminiscent of the 2008 Christmas period when the rebels killed hundreds of civilians in the area and surrounding regions.
"The LRA rebels have circulated pamphlets announcing that they are going to 'celebrate Christmas' in Niangara and Dungu," Ambroise Mbongi, head of a local NGO, told IRIN.
"The Niangara customary chief urged residents to resist and defend themselves using poisoned arrows and spears. There is panic and the population has started to leave Niangara," he added.
The LRA threats have turned Niangara into a ghost town, with some residents fleeing into the bush while others are stationed along the Isiro-Niangara and Isiro-Buta roads, he said.
To prevent LRA rebels from crossing the Bamokandi River, which separates Niangara from the area of Rungu, fishermen have moved their canoes, he said. "This time, they [the rebels] will have to swim to cross the river," he added.
Between 24 December 2008 and 17 January, LRA rebels killed at least 865 people and abducted about 160 children in the northeastern Haut-Uélé localities of Niangara, Dungu, Faradje and Doruma, according to Human Rights Watch.
At least 400 people were killed in a spate of attacks on 25 and 26 December alone, including about 100 killed in Faradje at a music concert.
As Christmas approaches, so do the rebels, according to Niangara's deputy, Jeanne Abakuba, who told IRIN the LRA were about 30km from Niangara, some 720km from Kisangani, capital of Orientale Province .
At the weekend, an alleged LRA "spy" was arrested on the outskirts of Niangara, and will be transferred to Kinshasa, said a police source.
On 13 December, about 26 rebels looted four clinics in the areas of Makanza, Ngilibi and Tapili in Niangara. The village of Makombo was also attacked. Two days later, the rebels shot six people, including a fisherman, who had helped them with a canoe to cross the Uéle River, a soldier and the Tapili village chief.
In March 2009, the rebels burned houses in Manziba, 15km from Niangara and invaded farms, forcing residents in surrounding villages towards Niangara, said Abakuba.
"The insecurity caused by the LRA is perennial. We are all the more worried that... government authorities do nothing to drive the rebels out of the country," said Célestin Bamongoyo, a member of Niangara civil society.
The Congolese army, which has been tracking down the LRA rebels since the end of 2008, maintains that measures are in place to avoid a repeat of the past killings.
"[To] say that the LRA will celebrate Christmas in Niangara and Dungu is nonsense, but we cannot stop them from dreaming. We have taken the necessary measures," the army's commandant in Orientale, Gén. Jean-Claude Kifwa, said.