Cyber activists striking at companies seen as enemies of WikiLeaks tried to block the website of online payment firm Moneybookers on Friday but denied their campaign was intended to damage economic activity.
Some campaigners communicating on Internet channels also called for attacks on official Dutch websites following the arrest in The Hague on Thursday of a 16-year-old boy suspected of involvement in the online campaign.
A string of U.S. institutions has ended services to WikiLeaks after the website published thousands of secret U.S. diplomatic reports that have caused tension between Washington and several of its allies.
The attack on Moneybookers appeared to have blocked the site for about two minutes at about 1235 GMT but it subsequently came back online. The activists promised to continue their assault and cited Interpol's site as a possible target.
In a statement, Moneybookers confirmed its website had been unavailable for a few minutes but the service was back up.
Online retail and web-hosting powerhouse Amazon stopped hosting WikiLeaks' website last week, and on Thursday it briefly became the main target of the pro-WikiLeaks campaigners -- before they admitted it was too big for them, for the moment.
The activists, who collectively call themselves Anonymous, said in a statement they were not hackers but rather "average Internet Citizens."
"We do not want to steal your personal information or credit card numbers. We also do not seek to attack critical infrastructure of companies such as MasterCard, Visa, PayPal or Amazon," the statement said.
"The point of Operation Payback was never to target critical infrastructure of any of the companies or organizations affected. Rather than doing that, we focused on their corporate websites, which is to say, their online 'public face'.
The Anonymous statement added that a lack of firepower was not the only reason the attack on Amazon had not succeeded. It felt "attacking a major online retailer when people are buying presents for their loved ones, would be in bad taste."
Activists said Moneybookers had became a target because it had informed WikiLeaks in August it had closed its account with the service to comply with investigations by several governments into possible money laundering and other matters.
The Anonymous statement followed one by WikiLeaks which said the website had no links to the cyber attacks, and neither supported nor condemned them. Some freedom of information campaigners sympathetic to WikiLeaks look askance at the attacks, saying its cause cannot be furthered by denying freedom of information to others.