Three parked buses were set ablaze by unidentified individuals in the early hours of Thursday.
The incident took place in front of Iris Hill Restaurant in the Batabaria area of Kotbari on the side of the Dhaka-Chittagong highway after 3am.
Comilla Sadar south model police station Officer-in-Charge (OC) Alamgir Hossain Bhuiyan said on receiving the information, police reached the spot and brought the fire under control.
Efforts are underway to identify those involved in the incident, the OC added.