Tunisia bus accident Photograph:( AFP )
The accident triggered renewed public anger over what one social media user called the country's "roads of death"
The health ministry said late Sunday that 17 people were also injured in the accident in a mountainous region popular with Tunisian tourists.
The disaster was one of the most deadly accidents in a country whose poor road safety record has sparked criticism of officials.
All those aboard the bus were Tunisian, the ministry said.
The bus had set off from Tunis towards the picturesque northern mountain town of Ain Draham, a popular autumn destination for domestic visitors.
The interior ministry had earlier reported the deaths of 22 out of the 43 people aboard, saying the bus had "fallen into a ravine after crashing through an iron barrier".
The health ministry said later that four more passengers had died of their injuries.
An AFP team that visited the site saw the twisted remains of the bus in the ravine near a river bed, surrounded by scattered bodies.
The top of the bus appeared to have been torn off and seats were strewn across the site.
President Kais Saied and outgoing Prime Minister Youssef Chahed later visited the site.
It was not immediately clear what caused the accident and forensic experts are investigating, but Tunisia's poorly-maintained roads have a reputation for being dangerous.
The World Health Organisation in 2015 reported that Tunisia had the second-worst traffic death rate per capita in North Africa, behind only war-torn Libya.
The accident triggered renewed public anger over what one social media user called the country's "roads of death".