Finland, Sweden, Norway, Denmark and Estonia are reportedly working on an offline credit card payment system to be used as a back-up in case of internet disruptions, as cyber security attacks continue to increase.

The move comes as Western intelligence agencies accuse Russia of carrying out various acts of sabotage against Europe, with the Baltic Sea region experiencing several cases of unexplained damage to critical underwater infrastructure in recent years.

Tuomas Valimaki, a member of the Bank of Finland's board, told Reuters that serious disruptions have increased due to political changes and that payments have become a target as they play a key role in everyday life.

Referring to the Ukraine-Russia conflict, he added: “There is a war in Europe, and around that war, there is all sorts of hybrid influence and harassment, which may involve disrupting or cutting connections.”

He also warned against Europe's heavy reliance on US companies Visa and Mastercard for card payments, calling for a reduction in this dependence.

“We may feel like we have options, to pay with debit or credit or with Apple Pay for example, but all of those function via the Visa and Mastercard infrastructure," he said.

Although the system is still under development, Valimaki said offline payments could involve the use of terminals that encrypt and store transaction data until the internet connection is restored.

He added that Finland will introduce a national system for instant payments in a few years, while offline payments will be available to consumers as early as next year.

The Swedish central bank also told Reuters that it is developing a system that will allow Swedes to make offline card payments to buy essential goods in the event of disruptions lasting up to seven days, adding the system could be ready by July next year.

The move comes as the European Central Bank looks to introduce a digital euro, which would allow instant payments.

The system aims to be a digital form of central bank money complementing existing cash and bank deposits to facilitate secure digital payments in the euro region.

---