Hizbullah may be planning to activate sleeper cells in New York and other big cities to stage an attack as the nuclear showdown with Iran heats up, according to a New York Post report Monday. The FBI and Justice Department have launched urgent new probes in New York and other cities targeting members of the Lebanese terror group. Law-enforcement and intelligence officials told The New York Post that about a dozen supporters of Hizbullah have been identified in recent weeks as operating in the New York area. Sources said FBI counter terrorism agents were monitoring the activities of these New York-based operatives as part of a nationwide effort to prevent a possible terror strike if the confrontation with Iran over its nuclear program spins out of control. Additional law-enforcement attention is being centered on the Iranian Mission to the United Nations, where there have already been three episodes in the last four years in which diplomats and security guards have been expelled for casing and photographing New York City subways and other potential targets. The nationwide effort to neutralize Hizbullah sleepers in the United States, being spearheaded by the FBI and Justice Department's counter terrorism divisions, was triggered in January in response to alarming reports that Iran's president, Mahmoud Ahmadinejad, met with leaders of Hizbullah and other terror groups during a visit to Syria. US officials, according to the New York Post stressed there is no intelligence information pointing to an imminent attack by Hizbullah, but officials said they have detected increased activity by Hizbullah operatives - including more heated rhetoric by its leaders and in Internet chat rooms as the US-Iran diplomatic showdown heats up. A US counter terrorism official called the latest effort a "major undertaking," with separate probes also under way in Los Angeles, Boston and Detroit.