WASHINGTON, Aug. 12 (Xinhuanet) -- Terrorists could attack New York, Los Angeles and Chicago around Sept. 11, using fuel tanker trucks to cause mass casualties, Federal Bureau Investigation(FBI)experts warned.

    The warning grew out of intelligence developed from an overseas source indicating that terrorists might seek to stage an anniversary attack by stealing fuel tanker trucks to explode gas stations, The New York Times on Friday quoted the experts as saying.

    Although it is unclear whether the attacks will occur simultaneously or be spread out over a certain period of time, the goal of the attack is very clear -- to collapse the US economy, according to the experts.

    The information has led FBI task forces in Los Angeles to alert other government and law enforcement officials privately this week about the threat.

    However, law enforcement officials in Washington and New York said that while they were aware of the warnings and were concerned about the Sept. 11 anniversary, they remained somewhat skeptical about the latest threat.

    "This information continues to be evaluated by the intelligence community," said Brian Roehrkasse, a spokesman for the Department of Homeland Security.

    US security agencies have long thought that fuel tanker trucks could be used in terrorist attacks.

    New York, Los Angeles and Chicago are considered at the top of potential targets, along with Washington D.C. and Las Vegas, because of their size, high profiles, symbolic value and past plots by al Qaida.

    Although urban transit systems remain on higher alert after last month's subway attacks in London, there were no immediate plans to raise the national threat level in the United States, the report said. Enditem