Police said the bus was transporting a group of devotees returning from a visit to the Nelligala International Buddhist Center.
The driver of the bus had reportedly lost control of the vehicle causing it to slide down a 15-metre slope and crash onto a tree.
The injured persons including the driver of the bus were admitted to the Peradeniya Hospital where a 79-year-old passenger died.
The deceased has been identified as a resident of Halpola, Pundaluoya while two of the injured passengers who are in critical condition have been transferred to the Kandy General Hospital.
Peradeniya Police are conducting further investigations into the incident.
by Shane Seneviratne