Government treasury transactions were also affected.
The bankers also demand recovery of bad loans and strong action against loan defaulters.
The strike call was given by two unions - All India Bank Employees' Association (AIBEA) and Bank Employees Federation of India (BEFI).
In a statement issued here, the AIBEA announced the large scale protest against the close down of six important nationalized banks i.e. Andhra Bank, Allahabad Bank, Corporation Bank, Syndicate Bank, Oriental Bank of Commerce and United Bank of India.
"Merger of banks is totally unwarranted in India as we need more banking services and opening of more branches to serve the people. Merger has so far resulted in closure of branches and hence it is a wrong policy," C.H. Venkatachalam, General Secretary, AIBEA said in the statement.
"Recovery of the huge bad loans is the top priority for the banks and merger of banks will change the priority. Hence merger is a bad idea," AIBEA said.