It's called
vishing or voice phising, the telephone equivalent of email phishing. It has been around for quite some time, but only seems to be hitting here now.
Only land line telephones are susceptible. They can play a tone down the line so it sounds to you like they have hung up and you can safely re-dial. Once you dial, they play more recordings asking for your bank account and log-in details so it sounds like you're on a bank's automated system. Once they have your details, they go after your money, setting up transfers, etc.
If you ever get any such call, use a mobile phone if possible to call your bank to confirm. AIB and BOI should be safe, in that AIB require you to use the gadget to authorise transactions, and BOI require you to confirm a code they send via post or text message before setting up new debits. I'm not sure about the arrangements of other banks. For BOI customers, they will never request more than 3 digits of your 6 digit PIN, so that can be another warning sign.