Sky internet has stopped working, with users unable to get online.
Engineers were aware of the issue and working to fix it, Sky said on its website.
It also confirmed that the problems were affecting phone calls, as well as internet connections.
“You might not be able to get online or make/receive phone calls due to a problem in your local area,” it said in an update.
“We’re working on fixing the problem and we’ll provide an update on this page once we’ve discovered what is causing the fault. We’re sorry for any inconvenience caused.”
In a statement, a Sky spokesperson apologised once again and said the problems were hitting customers in East London.
“We are investigating an issue with Sky Broadband and Talk affecting some customers in East London,” it said. “We are sorry for any inconvenience this is causing.”