Hacking group Lulz Security has said it was responsible for taking offline the website of the UK Serious Organised Crime agency (Soca).
Www.soca.gov.uk was unavailable on Monday afternoon, with an intermittent service restored later in the day.
As the agency launched an investigation, LulzSec tweeted: "Tango down - in the name of #AntiSec".
The group has hit a number of high-profile websites in recent weeks, including the CIA and US Senate.
Soca appeared to be the victim of a distributed denial of service (DDoS) attack, where a number of computers, under malicious control, overload their target with web requests.
A later LulzSec twitter posting seemed to confirm that.
"DDoS is of course our least powerful and most abundant ammunition. Government hacking is taking place right now behind the scenes," it said.
Over the weekend, the shadowy organisation declared that it would begin targeting government systems, calling the campaign Antisec.
In an online posting, LulzSec set out its agenda: "Top priority is to steal and leak any classified government information, including e-mail spools and documentation. Prime targets are banks and other high-ranking establishments."
Posts
