(CNN) -- Australia's national intelligence agency acknowledged Friday that its public website may have encountered problems after hackers said they had subjected it to a sustained campaign of cyber attacks.
The Australian Security Intelligence Organization "is aware that there may have been some technical issues with its public website," a spokesman for the organization said.
But the site "does not host any classified information and any disruption would not represent a risk to ASIO's business," the spokesman added, using the agency's abbreviated name.
The hackers, who appeared to have links to the loose collective Anonymous, said they had been launching attacks on the ASIO site and those of other Australian government agencies over the past few days, according to Twitter accounts under the names Anonymous Australia and OperationAustralia.
The ASIO site "has been down for some time now, And will be for the rest of the day!" OperationAustralia tweeted Friday morning, Sydney time. The site appeared to be functioning normally about seven hours later.
The OperationAustralia account, which uses the Twitter handle @Op_Australia and has about 400 followers, suggested the attacks were motivated by controversial proposals by the Australian authorities to have Internet users' web histories stored.
In recent years, Anonymous has been involved in some of the most high-profile cyberattacks on the Web -- hobbling the websites of governments and businesses, hacking into sites to reveal private data and, along the way, getting dubbed cyberterrorists by the authorities in the United States and elsewhere.
The network's motto is "We are Legion," and it describes itself as "a decentralized network of individuals focused on promoting access to information, free speech, and transparency."
CNN's Ben Brumfield contributed to this report.