The main website of the Vatican was inaccessible Wednesday after what appears to have been an attack by malicious hackers claiming to be affiliated with the Anonymous hacking collective.

An Associated Press story in USA Today quoted Vatican spokesman the Rev. Federico Lombardi as confirming the site's unavailability but declining to comment on the likely source of the problem.

A website claiming to be the official blog of Anonymous in Italy on Wednesday posted a message taking credit for the attack. A rough Google translation of the message, which is in Italian, suggests that the site was taken down to protest church doctrine and the molestation of children, by clergy members.

The message makes references to the church's alleged prosecution of detractors, its allegedly anachronistic views and the sexual abuse of children by priests.

As with other Anonymous posts, it is hard to verify if the attackers are part of the hacking collective and whether they are responsible for the attack on the Vatican site. Anonymous is a decentralised, loosely organised collection of hactivists with no real leadership. In the past, hackers have claimed actions on behalf of Anonymous only to have others within the collective deny those actions.

The attack on the Vatican is the second high-profile incident since Tuesday, when US law enforcement officials announced that they had arrested several influential members of Anonymous and a splinter group, Lulzsec.

As of 3pm ET, the main Vatican website at remained unavailable. The AP story quoted Lombardi as saying the Vatican had no idea how long it would take the restore the site.

The news comes just a week after security firm Imperva published a detailed analysis of an unsuccessful attack by Anonymous on one of its customers. According to The New York Times, the target in question was the Vatican, although Imperva declined to confirm this, in an attempt to avoid a repeat attack on its customer.

Earlier Wednesday, attackers claiming to be from Anonymous broke into Panda Security 's PandaLabs website and defaced it with a rant against the arrest of "Sabu," the former head of LulzSec, whose cooperation with the FBI led to Wednesday's arrests.

The Panda site that was hacked was hosted on an external server and was used only for marketing purposes and to host the company's blogs, according to Panda Security . The PandaLabs site was down for several hours earlier today as a result of the attack. This afternoon, efforts to get to the PandaLabs site were redirected to Panda Security's main web page.