Mussa Taibu Mbeya Regional Police Commander confirmed the accident saying it happened at Mbalizi Hill on the outskirts of Mbeya city in the afternoon and involved three commuter buses and a truck Xinhua reported.
Taibu said that the accident occurred when a truck carrying a container rammed into a commuter mini-bus and killed 20 people on the spot.
After hitting the first mini-bus the truck got out of the way and hit other two mini-buses before plunging into a river said Taibu.
The truck was heading to the Tanzania-Zambia border town of Tunduma from the south-western city of Mbeya according to the police.
He said the injured people have been sent to Mbalizi District Designated Hospital and Mbeya Zonal Referral Hospital.
The accident came only three days after another road accident in which five people died and three injured happened in Mtwara Region in Tanzania.
Reports have it that reckless driving and poor road infrastructures as among the major factors fueling road accidents in Tanzania.
--IANS ahm/