BT has said some of its customers are experiencing problems with its broadband and telephone services.
"Sorry, we're aware of a problem & working to fix ASAP," it tweeted shortly after 0900 BST.
The firm's Plusnet broadband division has also said that it is facing issues.
BT said that "power issues at one of our internet peering partners' sites in London" were the cause. "Engineers are working to fix things as fast as possible," it added.
A spokeswoman was unable to provide more information.
You're darn tooting we are experiencing problems. I seem to be alright on http and https, but the SQL, RDP and Skype ports have all gone for a Burton.