A bank employee Ushashri Ghosh suffered injury in broken glass when she tried to rush out of the bank at about 1 pm amid fire spreading, sources said.
She was admitted to Purulia Sadar Hospital, officials said, adding that other employees and customers could manage to come out safely.
Two fire tenders doused the flames after two hours and the extent of damage has not been assessed yet, District Magistrate Avanindra Singh whose office is close to the bank, said.
The firemen said the cause of fire was electrical short-circuit and forensic tests are being carried out.