Two buses travelling in opposite directions "met head on" while trying to overtake two other vehicles – a lorry and a car – on the Kampala-Gulu Highway at 00:15 local time (21:15 GMT), according to the Uganda Police Force.
One of the buses swerved in an attempt to avoid a crash, but in the process caused a "head on and side collision" that led to a "chain reaction" in which other vehicles lost control and overturned.
As well as the fatalities, passengers of the vehicles involved and several others were injured, police said. An investigation has been launched.
