The United States' Central Intelligence Agency (CIA) says it is checking reports that its public website was attacked by computer hackers.
The "Lulz Security" (LulzSec) group of hackers said in a Twitter message that it had launched an attack on the cia.gov website.
Some difficulty was reported in accessing the website on the evening of June 15, but it was unclear if the difficulty was caused by the claimed hacker attack.
The LulzSec group earlier this week claimed an attack on a public website of the U.S. Senate and said it had stolen data from the legislative body's computer servers.
The group has also claimed responsibility for a series of other recent cyber assaults, including attacks on Sony's online operations and the website of the U.S. non-profit Public Broadcasting System.
compiled from agency reports