A speeding bus overturned killing 16 people outside Tanzania's commercial capital Dar es Salaam, police said on Tuesday.
The bus, carrying 48 adults and about 10 children aged between one and eight, was on its way to the administrative capital Dodoma on Monday when it rolled. Forty-one people were injured.
"The number of people who died were eight men and eight women," said Ephraim Mrema of the Coast Region police.
"The accident was caused by high speed. While overtaking, the driver saw a tanker in front of him. He drove to the extreme right side of the road ... knocked a bridge post and thereafter the bus overturned."
Pictures in Tanzanian media showed the bus with its roof ripped off and front end smashed.
Mrema said the bus driver was in police custody while receiving treatment for injuries.
Three months ago a bus plunged into a river in northern Tanzania, killing 54 people.
Overcrowding, speeding and deadly accidents are common on public transport across Africa.