Hackers who claimed responsibility for online attacks of Sony Corp. and the CIA said they compromised the security of more than 1,000 accounts of a Connecticut-based FBI partner organisation, hours before releasing a web manifesto calling for "war" on governments that control the internet.

The online collective Lulz Security said it attacked a local section of InfraGard, a partnership between the FBI and the private sector to share security information. Connecticut InfraGard's website was down on Monday afternoon.

The FBI was aware of the attack and that the website had been shut down as a precaution, agency spokeswoman Jenny Shearer said. She declined to comment on the extent of any damage.

Lulz tweeted Sunday night that its Connecticut attack had "compromised 1000 plus FBI-affiliated members." The group said it would not leak the user information but would embarrass the FBI with "simple hacks." It did not provide details on the information it said was compromised.

InfraGard is an association of businesses, academic institutions and law enforcement agencies dedicated to sharing information to prevent hostile acts against the United States, according to its website. Business representatives who participate get access to security information from government sources such as the FBI and Department of Homeland Security and can participate in discussions with others in the IT-security field.

This month, the Atlanta chapter of InfraGard said hackers stole 180 passwords from its members and leaked them online. Lulz also claimed responsibility for that attack, saying it was a response to a report that the Pentagon was considering whether to classify types of cyber-attacks as acts of war.

After announcing the Connecticut attack, the group issues its statement calling for a united hacker effort against governments and organisations that control the Internet.