Unidentified miscreants allegedly set fire to a single-storey building of Grameen Bank in Chandura area of Brahmanbaria's Bijoynagar upazila early today, an official said.

The fire burned furniture and important documents of the branch, though the vault containing cash remained unharmed, Md Kalim Uddin, manager of the Chandura branch, told The Daily Star.

"The incident took place around 2:00am when someone poured petrol and set fire from outside," he said.

"The night guard noticed the blaze and alerted us. Locals then helped bring the fire under control. But it is still unknown who was behind the arson attack," he added.

Firefighters later arrived and extinguished the flames completely. A written complaint will be filed with the local police station, the bank official said further.

Wasi Azad, in-charge of the Bijoynagar Upazila Fire Service, said, "We rushed to the spot after receiving the fire alert and found the blaze mostly under control. Some papers and furniture were damaged, but no money was harmed."

Contacted, Bijoynagar Police Station Officer-in-Charge (OC) Shahidul Islam said, "I visited the spot at night after being informed about the fire. Inside the office room of the bank, I found that wooden racks used to store loan records and registers had been burned....The branch manager has filed a general diary regarding the incident."