A loud explosion was Sunday heard at Matomachi near Quality Supermarket – Naalya in Namugongo, outside Kampala.
Police rushed and cordoned off the scene.
It was later reported that the explosion started at Marcos Gym and Spa injuring five people.
Counter Terrorism experts said the blast was due to a steam bath boiler which had damaged valves that sealed the hot pressure from being released from a container that was being heat.
Kampala Metropolitan Police Spokesperson Patrick Onyango said those hurt were employees of the Spa.
The owner Martha Muhangi has been arrested for negligence.