The activists barged into the SBI building and raised slogans against the move, bank sources said.
The activists, however, could not meet the SBI General Manager S Venkataraman, who is the Kerala head of the SBI.
They entered the office, sat in front of Venkataraman's cabin and shouted slogans against Prime Minister Narendra Modi and Centre's reported decision to waive bad loans.
They were later whisked off by police.
Reports in a section of the media had stated that SBI had decided to write off loans of some defaulters including liquor baron Vijay Mallya.