The Ugandan army said on Monday it had killed 12 people in weekend bombing raids against tribal warriors accused of shooting at a military helicopter over the country's restive north-east Karamoja region.
But sources in the area said the death toll was much higher and spoke of residents reporting as many as 500 people killed with many more injuries from the bombing near the Kenyan-Ugandan border town of Kotido.
Army spokesman Major Felix Kulaije dismissed reports of mass casualties as "nonsense" but confirmed that military aircraft had conducted bombing around Kotido, 600 kilometres (372 miles) north-east of Kampala.
"On Saturday, there were bombings in areas near the border after ground-to-air attacks on one of our helicopters," he said. "Those killed, who were about 12, included some Kenyans who had crossed over to Uganda."
"That is nonsense," Kulaije told AFP when asked about reports of widespread carnage. "We do not take revenge and any suggestion that there are high casualty figures is simply nonsense."
Despite his denial, community leaders in the area near Kotido said the bombings had targeted densely populated villages.
"The army has been bombing for some time, but on Saturday, they dropped bombs in populated areas and many people were killed," said one who spoke to AFP on condition of anonymity, fearing reprisals.
"Some people are putting the death toll at over 500, but we can't verify that yet," the community leader said.