FILE PHOTO: A sign is displayed outside a branch of the TSB bank in central London March 12, 2015.. REUTERS/Neil Hall

(Reuters) - Online banking for British retail bank TSB suffered a temporary outage on Monday, sparking complaints from customers who took to social media to say that they were unable to log on.

“We’re sorry that some of our customers experienced a temporary issue with our Internet Banking service for a short period this evening,” TSB said in emailed comments.

“Service levels have returned to normal and we’d like to apologise for any inconvenience this may have caused.”

TSB is owned by Spain's Sabadell SABE.MC.