Miscreants set fire to Grameen Bank office at Sharshadi Bazar in Feni Sadar upazila early Thursday.
The fire damaged three motorbikes and furniture on the office premises.
Police said the miscreants poured petrol from outside the main gate and ignited the fire around 3:30am.
Seeing the fire at the stairway, the security guards started screaming seeking help.
Hearing this, some officials who stay on the second floor of the same building informed fire service personnel who later brought the fire under control.
Branch manager Ashok Kumar Debnath said the miscreants had jumped off the boundary wall to enter the premises before setting fire to the gate area.
Grameen Bank office set on fire in Kushtia
Locals initially helped control the fire before firefighters arrived, he said.
Feni Model Police Station Inspector (investigation) Sajal Kanti Dash said police visited the spot after receiving information.
The bank authorities lodged a complaint in this regard and action would be taken accordingly, he added.