Washington (CNN) -- Computer hackers who promise "high-quality entertainment at your expense" claimed to have taken down the Central Intelligence Agency website in support of WikiLeaks, but on Thursday the website appeared to be operating normally.
"WikiLeaks supporters, LulzSec, take down CIA ... who has task force into WikiLeaks," the hackers, who call themselves "Lulz Security," said on Twitter late Wednesday.
WikiLeaks, Julian Assange's group that facilitates the release of secret information, reposted the message on its own Twitter feed.
About an hour later, they said, "Goodnight twitter. The CIA anti-lizards will probably rise from the packet sea while we rest our shining-yet-saturated power field arrays."
CIA spokeswoman Jennifer Youngblood said Thursday that the agency's public, unclassified website "experienced technical issues that caused it to respond slowly for a short period of time yesterday evening. Those issues have been resolved."
The problem had no impact on anything classified, she said.
Separately, a U.S. official told CNN there was no hacking, no intrusion, no access into the CIA site. Instead, "the server was overwhelmed," this official said.
A law enforcement official also downplayed the incident, telling CNN it compared to attacking a bridge with graffiti.
The hackers group, using the name The Lulz Boat, claimed responsibility last month for hacking the PBS news website in the United States and posting a story saying that rapper Tupac Shakur, who has been dead for nearly 15 years, was alive and living in New Zealand.
That hack followed a PBS documentary on WikiLeaks. The Lulz Boat said it was "less than impressed" with the program, "WikiSecrets."
CNN's Carol Cratty and Jeane Meserve contributed to this report.