NatWest customers were locked out of online banking services for the second time in a week, as the accident-prone UK bank fell victim to a Distributed Denial of Services attack.
The disruption to customer service lasted for an hour from 11:30.
An RBS spokesman apologised to customers for the latest hiccup. "Due to a surge in Internet traffic deliberately directed at the NatWest Website, customers experienced difficulties accessing some of our customer Websites today. We have taken the appropriate action to restore the affected Websites. At no time was there any risk to customers. We apologise for the inconvenience caused."
Earlier this week RBS chief executive Ross McEwan blamed decades of underinvestment in IT for a systems blow-out that left customers unable to access their money or pay for goods on Cyber Monday, traditionally the busiest shopping day of the year.
RBS stresses that the latest incident was not in any way connected to Monday's IT failure.