NEW YORK -- ABC News is working to confirm the authenticity of a videotape purportedly made by a Middle Eastern terrorist group that threatens a large-scale attack on the United States. ABC has given copies of the video to the FBI and CIA, the network confirmed Wednesday. The hourlong tape reportedly includes men, their faces obscured by headdresses, making threats against the United States. ABC News confirmed the tape's existence but declined to discuss its content. The news division also wouldn't discuss whether it would report on the tape or broadcast part of it. "Neither ABC News nor those intelligence agencies have as of yet authenticated that tape," ABC News spokesman Jeffrey Schneider said. "It would be completely irresponsible for any news organization to report or broadcast a tape of that nature without confirming it." ABC News got a copy of the tape from a source in Pakistan over the weekend. The news division sent copies to the CIA and FBI on Monday, the same day the tape arrived in the news division's New York headquarters. "We have been working around the clock on this story," Schneider said. Details of the tape first appeared in the Drudge Report Web site on Wednesday afternoon.