The websites of CNN and Gawker were briefly inaccessible for some users on Thursday following a hacker attack that crippled the BBC’s online operations.

CNN’s site returned to normal after about 30 minutes, according to people who posted about the outage on Twitter. Gawker’s site returned more slowly.

Neither site disclosed what had caused the outages nor was there any indication that the outages were linked. In a tweet after restoring service, CNN merely said:

Earlier in the day, the BBC’s main website became inaccessible for several hours in the morning after what a source inside the British news organization reportedly described as a distributed denial of service attack. Such attacks overload websites with automated traffic that blocks human visitors from being able to download pages.

For more about hackings, watch this Fortune video:

Officially, the BBC provided no explanation for the outage other than to say the problem was caused by a “technical issue.” Hours later, the BBC said the website had returned to normal operations and apologized for the problem.