LONDON, United Kingdom (AFP) — Payment systems giant Visa was struggling to process transactions in Europe on Friday and said it was rapidly trying to fix the issue.

The blockage has left some customers stuck at the tills in stores across the continent and queueing at cash machines.

“We are currently experiencing a service disruption which is preventing some Visa transactions in Europe from being processed,” a Visa spokesman told AFP.

“We are investigating the cause and working as quickly as possible to resolve the situation.”

The spokesman could not say how many Visa users across Europe had been affected.

Visa users took to social media to complain and banks tried to explain the situation their customers.

HSBC bank’s UK Twitter account said: “From what we understand there are still intermittent issues but services are slowly recovering.”

Paymentsense, which provides card machines, online payment gateways and virtual terminals to some 60,000 independent businesses in Britain and Ireland, advised users to try paying via contactless transactions.

“We have been informed that Visa has corrected the outage and transactions are now starting to go through. There is still some intermittency however, we believe this is due to a backlog of transactions,” it said.

“We now understand that contactless transactions have a better chance of going through.”

It is understood the Bank of England is aware of the issue and is in touch with Visa.

The Royal Bank of Scotland’s Twitter help account said cash machine withdrawals were unaffected.

“This is an industry wide issue which is being investigated as a matter of urgency and we apologise for any inconvenience. ATM and MasterCard transactions are not impacted,” it said.