The Ugandan army has killed seven civilians and injured 16 in a weekend of violence near Gulu in the north.
The shooting took place in the Lalogi camp, where victims had taken shelter from attacks by the rebel Lord's Resistance Army.
They were shot while protesting over the killing of a teenage boy.
A spokesman for the army said the youth was mistaken for a rebel and killed, and that the soldier responsible had been arrested.
Humanitarian sources confirmed to the BBC that seven civilians were shot dead by the soldiers and a further 16 are in hospital with gunshot wounds.
The teenage boy was shot dead by a soldier in the camp on Sunday night.
Angered by the incident, a crowd went to the barracks to protest.
The Ugandan Army says the people turned violent and shots were fired into the air to disperse them.
However, the deaths and injuries have cast doubt on this explanation.
Rebels killed
The BBC's Will Ross in Kampala says the incident is likely to overshadow the news that 10 LRA fighters, including a senior commander, Brigadier Francis Kapere, were killed by the army over the weekend.
The army said Brigadier Kapere was killed in an ambush, also in Gulu district.
Some 1.5m people have been displaced by the 20-year conflict between the LRA and the Ugandan government.
The conflict has gained notoriety for the LRA's massacres and its tactic of kidnapping children for use as soldiers and sex slaves.
Several senior commanders of the LRA are wanted by the International Criminal Court in The Hague, and the governments of Uganda and Sudan have agreed to cooperate.
