LONDON: Credit card giant MasterCard and the Swedish prosecutor's office came under cyber attack Wednesday as WikiLeaks supporters vowed to retaliate for moves against Julian Assange after the release of US diplomatic cables that angered and embarrassed Washington. The Swedish prosecution authority, whose arrest order for Assange over accusations of sexual offenses led a British court to remand the 39-year-old WikiLeaks website founder in custody, said it had reported the online attack to police. “Of course, it's easy to think it has a connection with WikiLeaks but we can't confirm that,” prosecution authority web editor Fredrik Berg told Reuters Television. Assange supporters also went for the corporate website of credit card firm MasterCard in apparent retaliation for its blocking of donations to the WikiLeaks website. “We are glad to tell you that http://www.mastercard.com/ is down and it's confirmed!” said an entry on the Twitter feed of a group calling itself AnonOps, which says it fights against censorship and “copywrong.” Mark Stephens, Assange's principal lawyer in London, denied that the WikiLeaks founder had ordered the cyber strikes. Assange “did not give instructions to hack” the company websites, Stephens told Reuters. MasterCard said its systems had not been compromised by what it called “a concentrated effort to flood our corporate website with traffic and slow access.” “We are working to restore normal service levels,” the company said in a statement. Assange spent the night in a British jail and will appear for a hearing on Dec. 14. Assange has angered US authorities and triggered headlines worldwide by publishing the secret cables. Australian Foreign Minister Kevin Rudd said the people who originally leaked the documents, not Assange, were legally liable and the leaks raised questions over the “adequacy” of US security. “Mr. Assange is not himself responsible for the unauthorized release of 250,000 documents from the US diplomatic communications network,” Rudd told Reuters in an interview. “The Americans are responsible for that,” said Rudd, described in one leaked US cable as a “control freak.” New revelations continue The latest cables, reported in Britain's Guardian newspaper, said Libyan leader Muammar Gaddafi made threats to cut trade with Britain and warned of “enormous repercussions” if the Libyan convicted of the 1988 Lockerbie airline bombing died in a Scottish jail. He was freed in August 2009.