Downpours trigger fatal Uganda landslides
Bridges were washed away and some 200 homes destroyed in heavy rains that have cut off access to some areas.
"It is a major landslide, which has killed about 15 people as from the reports so far received and 50 others are undergoing treatment in hospital," said local official Godfrey Mucunguzi.
Authorities in the area, which includes the hard-hit villages of Humya and Bukhonzo in the Bundibugyo district, have called for help from the government to rescue anyone trapped and to evacuate the injured.
"If the rains do not stop the number of casualties are expected to go up," Mucunguzi added.
The news comes a day after authorities announced that at least 49 people had been killed at the weekend in neighbouring Rwanda after landslides caused by heavy rains.
Landslides are not unusual in Rwanda but this year's rainy season has been particularly deadly with at least 67 people killed from January to April.
Of that total, 12 people died on a single night in the suburbs of the capital Kigali, where 1,500 homes were damaged during rainstorms.
Authorities blame the El Nino weather phenomenon for the disasters.