The driver lost control while taking a corner near the Kamatira Forest Reserve on Wednesday. The bus hit a ditch and then rolled down a deep valley.

The Red Cross said it had so far rescued 65 people from the wreckage, and was waiting for cranes to arrive to remove at least two bodies still trapped in the mangled remains.

One survivor blamed the driver for the crash, saying he was driving too fast and ignored requests to slow down.

"There were pleas from passengers to reduce the speed, but he failed to listen," George Owino told the Standard newspaper.

Deadly road accidents are a common occurrence in Kenya, where ancient buses and commuter minibuses known as matatus, driven erratically at breakneck speeds, cause head-on collisions or simply drive off the road.