The hacker group LulzSec, which has claimed responsibility for several high-publicity attacks on Sony, Nintendo and even the NHS, yesterday posted a message on its website claiming responsibility for a new successful cyber attack on the U.S. Senate.

LulzSec reported in its post that the attack happened over the weekend and targeted the U.S. Senate's website.

The hack reportedly saw the group break into a public portion of the Senate's website. The Senate has since clarified that the group did not manage to breach the firewall protecting the more sensitive portion of the network.

Martina Bradford, the deputy Senate sergeant at arms commented , "We were responding to their allegations. Basically what we're saying that the server they got into is for public access and is in the public side".

LulzSec's post indicated a possible motivation for its attack as being the U.S. governments recent policy of treating all cyber attacks in the same manner as a real-world attack.

In the subsequent post the group put on its website displaying the data allegedly stolen, LulzSec commented:

"We don't like the US government very much. Their boats are weak, their lulz are low, and their sites aren't very secure. In an attempt to help them fix their issues, we've decided to donate additional lulz in the form of owning them some more!

"This is a small, just-for-kicks release of some internal data from - is this an act of war, gentlemen? Problem?"

Responding to LulzSec's announcement the Senate's security released a statement promising that no sensitive data had been stolen, "Although this intrusion is inconvenient, it does not compromise the security of the Senate's network, its members or staff.

"Specifically, there is no individual user account information on the server supporting that could have been compromised."

The news of LulzSec's most recent cyber raid comes just after both the U.S. and U.K. governments announced new policies and initiatives designed to combat the "growing threat".

Already this month high-profile financial firm Citibank and the International Monetary Fund have been revealed as suffering similar cyber attacks.

While LulzSec is most recently known for its attacks on the computer games industry, the attack on the U.S. Senate is not the first the group has enacted for political reasons. LulzSec has previously claimed responsibility for successful cyber attacks on websites in Syria, Tunisia, Egypt and India citing political motivations.

UPDATE: The groups has also reported an attack on games developer Bethesda Softworks.