Forty three people died and several others injured on Wednesday when a bus travelling to Zambia on the Harare-Chirundu Road veered off the road and rammed onto a tree.
Police spokesperson Senior Assistant Commissioner Charity Charamba said more passengers may die due to the serious injuries they suffered in the accident.
She said initial indications are that the accident was caused by speeding and overloading of passengers.
Some of the people who were inside the bus claimed that the driver of the Lion King bus was speeding even after he was asked to slow down by frightened passengers.
Tapiwa Sande said he is happy to be alive after witnessing one of the worst accidents.
"The bus was speeding and we told the driver about our concerns when we were at Banket but he did not slowdown.
"He continued speeding and I suspect that he slept while driving and he nearly hit an oncoming vehicle but the bus left the road and when he attempted to get back to the main tarred road the bus burst a tyre."
Several accidents in Zimbabwe have been attributed to human error and the poor state of the roads owing to lack of funds to maintain them.