Chandigarh, May 13 (IANS) Three passengers were burnt alive and 20 others injured when a private bus caught fire near Rampura Phul town in south-west Punjab on Saturday evening, police said.

The injured were rushed to hospitals in Rampura Phul and Bathinda, police said.

The high casualties occurred due to the fact that it was an air-conditioned bus and the passengers were trapped inside for some time after the fire broke out.

Police said the cause of the fire bus was being ascertained.