SBIReuters file

State Bank of India (SBI) will be issuing fresh debit cards to customers whose cards were blocked as a preventive measure by the country's largest lender, following a massive security breach detected a few days ago.

"We have set an internal target of seven to 10 days for issuing the new debit cards to the customers whose cards have been blocked," IANS quoted SBI chief general manager (Kolkata Circle) Partha Pratim Sengupta as saying on Friday in Kolkata.

SBI had blocked about 6 lakh debit cards after card network companies NPCI, Mastercard and Visa informed various banks in India about a potential risk to some cards in India owing to a data breach. Overall, about 32 lakh debit cards will be re-issued to customers of different Indian banks.

To ensure safety of transactions, the bank wants its customers to use only SBI ATMs "at the moment."

The government of India played down the security breach, saying only 0.5 percent of the total number of cards were affected by the incident.

In a statement on Thursday, the National Payments Corporation of India (NPCI) said the data compromise involved 641 customers of 19 Indian banks, resulting in fraudulent withdrawals of Rs 1.30 crore.

"All affected banks have been alerted by all card networks that a total card base of about 3.2 million could have been possibly compromised. Out of this 0.6 million are RuPay cards," the umbrella organisation for all retail payments systems in India said in the statement.

SBI has also started posting tweets on how to use debit cards safely.