Several other pupils and school staff were injured in the accident, which happened as the group returned from an educational tour.
According to preliminary investigations, the bus developed a mechanical fault before the driver lost control while descending Chekwatit Hill, a section of road known for frequent fatal crashes.
Education Minister John Chrysostom Muyingo said the suspension of school trips is a temporary safety measure pending the outcome of investigations.
“As an immediate precautionary measure, we must do something about the safety of our children,” Muyingo said. “The nation has suffered a great loss. I would like us to work hand in hand so that those who survived are well taken care of.”
Traffic Police spokesperson Michael Kananura said the driver lost control of the bus, which veered off the road, struck a large roadside rock and overturned.
The bus, carrying pupils from King David Junior School in Ndejje, crashed at around 8:00 p.m. local time in Chekwatit village.
Local Government Minister Balaam Ateenyi Barugahara confirmed that the victims included the school’s founder and director, Tadeo Ssekade.
“Sadly, 20 children and one adult, who happens to be the founder and director, Mr. Tadeo Ssekade, have gone to be with the Lord,” Barugahara said in a post on X.
Witnesses shared videos showing the bus extensively damaged as residents rushed to rescue the injured.
Local media reported the pupils were returning from a study tour to the Sipi Falls tourist area.
Road crashes remain a major safety concern in Uganda, with authorities citing speeding, poor vehicle maintenance and hazardous roads as leading causes of fatalities.
The latest tragedy has renewed concerns over the safety of school transport following several serious bus accidents reported across the country in recent weeks.