The bus rolled 196 feet into the ravine, flinging some passengers away, the New Straits Times reported.
Rescuers working to locate survivors and the dead rigged a bucket system to haul them up to the road, the newspaper said.
At least five people were seriously injured.
Rescuers said the momentum of the bus' descent into the ravine was slowed by trees and undergrowth.
Notable deaths of 2014 [PHOTOS]