A large number of ATMs of both PSU and private banks ran out of cash following the two strike observed by the employees of the national banks.

In some parts of the country, the problem was intensified, as bank unions aggressively forced the security watch to shutter down the ATMs.

Most of the on-site and off-site ATMs in Kolkata were closed for public use - "We had refilled money but could not operate the ATMs due to protest by strikers," said an SBI spokesperson.

Similar reasons were offered by Axis Bank, though ICICI Bank spokesperson reasoned that ATMs were closed due to security reasons.

"ATMs are part of banking network. So, they can't operate during a bank strike," said Ashok Mukherjee, secretary of SBI Staff Association.

Quoting a private bank on the situation, ''It's a new situation for us. Now that all ATMs are linked and a customer from any bank can withdraw money from the ATM of any other bank, there was huge pressure on the ATMs of banks such as ICICI Bank and HDFC Bank."

However, the problem of ‘out-of-cash' is temporary, as these machines are monitored electronically on regular basis. Thus as soon as these run out of cash stock, the bank is alerted for replenishment.

Over 10 lakh employees of state-owned banks participated in a two-day strike called by United Forum of Bank Unions (UFBU) to protest against the IBA verdict of 13 percent pay hike and the withdrawal of alternate pension fund offer.

Though private and foreign banks are not participating, critical banking operations like cheque clearances, cash transactions have been hit hard as public sector banks in India control over 70% of the banking operations.