The Reserve Bank of India (RBI) has fined at least 19 banks, including ICICI, State Bank of India and Yes Bank, for failing to comply with rules on using the Swift network.

Stock exchange filings reviewed by Reuters show the fines, which total more than 400 million rupees (About $5.7 million) across the banks.

Details on the compliance failures are scant but are related to rules introduced last year requiring banks to connect the Swift interbank messaging system with their core banking platforms.

Following audits, offending banks were issued show-cause notices and have been fined, although many say that they have now remedied the problems.

The RBI crackdown is understood to be a response to last year's $2 billion fraud at Punjab National Bank, which saw Swift used for unauthorised credit guarantees to businesses linked to billionaire jeweller Nirav Modi.