Al-Qaida is planning a large-scale terror attack on a US target this summer, a senior CIA official told ABC News. "This is reminiscent of the warnings and intelligence we were getting in the summer of 2001," the official said. US officials have not confirmed the report, based on a classified document, and Homeland Security Secretary Michael Chertoff told ABC that the United States did not "have any specific credible evidence that there [was] an attack focused on the United States at this point." ABC also published a document presented to Homeland Security before the recent failed attacks on London and Glasgow. The document warned that terrorists were planning attacks on airports and planes in Glasgow and Prague. According to the British sources, the information had failed to reach Scottish security forces before the attacks. Chertoff responded that "everything that we get is shared virtually instantaneously with our counterparts in Britain and vice versa."