Police said a customer and a bank official were injured in the scuffle with the robbers.
Senior police officers, including the inspector general, reached the bank for investigations but till evening there was no clue.
A forensic team also reached the spot.
The gang come in a van, and there were two others on a motor bike standing guard.
Bank officials said at around 1.40 p.m. the robbers barged in with pistols. The manager was forcibly taken to the strongroom and keys snatched from him. The cashier who tried to put up a resistance was hit with the butt of the pistol. Bleeding profusely he was rushed to the hospital.