The hand written note, found near the staircase of the building at Gumanpura area of the city, claimed that a bomb had been planted in the bank.
A thorough search was carried out in the building and adjoining areas. However, no bomb or explosive was recovered from the building or from the nearby areas.
The agent branch office of Life Insurance Cooperation also runs in the same building on the second floor. The note said that the employees of both the offices should "evacuate the building to save their life as the bomb might go off at any time", Station House Officer (SHO) Sanjay Sharma said.
"It appears to be a mischievous act of some anti social element to spread panic in the city," he said.
No arrest has been made so far, police said, adding footage of CCTV cameras of the bank was also being investigated to identify the culprit.