U.S. intelligence officials had several warnings that terrorists might attack the United States on its home soil -- even using airplanes as weapons -- well before the September 11, 2001 attacks, two congressional committees said in a report. In 1998, U.S. intelligence had information that a group of unidentified Arabs planned to fly an explosives-laden airplane into the World Trade Center, according to a joint inquiry of the House and Senate intelligence committees. However, the Federal Aviation Administration found the plot highly unlikely given the state of that foreign country's aviation program," and believed a flight originating outside the United States would be detected before it reached its target inside the country, the report said. "The FBI's New York office took no action on the information," it said. Another alert came just a month before the attacks, the report said, when the CIA sent a message to the FAA warning of a possible hijacking "or an act of sabotage against a commercial airliner." The information was linked to a group of Pakistanis based in South America. That warning did not mention using an airliner as a weapon and, the report said, "there was apparently little, if any, effort by intelligence community analysts to produce any strategic assessments of terrorists using aircraft as weapons."