A group calling itself "Secret Organization — al-Qaeda in Europe" has posted a claim of responsibility for the series of blasts in London, a German magazine reported Thursday. Der Spiegel magazine reported that the group posted its message on a Web site popular with Islamic militants, which it did not name. It said the group claimed the explosions were in retaliation for Britain's involvement in Iraq and Afghanistan. "Rejoice, Islamic nation. Rejoice, Arab world. The time has come for vengeance against the Zionist crusader government of Britain in response to the massacres Britain committed in Iraq and Afghanistan," read the statement, a photograph of which was displayed on Der Spiegel's Web site. "The heroic mujahedeen carried out a blessed attack in London, and now Britain is burning with fear and terror, from north to south, east to west," it said. The statement went on the warn the governments of Denmark and Italy that they would face "the same punishment" if they fail to withdraw their troops from Iraq and Afghanistan.