Bank of Ireland has warned customers that money withdrawn from ATMs will still be debited from their accounts after some people with low balances reported being able to take out €1,000 (£857) in cash following an IT failure.

The Irish police service, An Garda Siochana, said it was aware of an “unusual volume of activity” at some ATMs across the country following reports of people queuing to withdraw money at Bank of Ireland cash machines.

The gardai also said it was aware of issues relating to banking services on Tuesday after the bank’s online and app services were down. Officers were on Tuesday night reported to be guarding some cash machines after videos were posted on social media of huge queues forming in Dublin, Limerick and Dundalk.

In a statement to the PA news agency, a Bank of Ireland spokesman said: “We would like to remind customers that if they transfer or withdraw funds – including over their normal limits – this money will be debited from their account.

“While we are conscious customers may not be able to check their balance at this time, they should not withdraw or transfer funds if they are likely to become overdrawn.”

Police also said they would “remind people of their personal responsibility in carrying out their personal banking”.

A spokesman for banking technology firm Revolut said it was “looking into” claims that excess amounts of money had been transferred into customer’s accounts from Bank of Ireland.

A fault with the online app allowed people who have no money in their account to transfer up to €500 into a Revolut account, the Irish Independent reported.

Earlier, Bank of Ireland said it does not have an estimated time for when its mobile app and web service will be restored.

The bank has told customers that its technical team is working to rectify the difficulties as a “high priority”.

Bank of Ireland in Navan, major fault allowing money to be drawn out even if you have none in the bank. Where are the Gardai? pic.twitter.com/XujVzIhdAr

— Chris Rattigan ©️®️™️ (@ChrisRattigan1) August 15, 2023

Customers reported having no access to their accounts for hours and being unable to transfer money for “important payments”.

Apologising to users, Bank of Ireland said: “We are aware that customers using our mobile app and 365Online are currently experiencing difficulties.

“We are working to fix this issue as quickly as possible and apologise for any inconvenience caused.”

The bank also acknowledged that some customers were having difficulties withdrawing cash from ATMs.

Shortly before 10pm on Tuesday, the bank added that it did not “have an ETA” for the restoration of services.