AD Quality Auto 360p 720p 1080p Top articles1/5READ MOREThe top 10 theme park moments of 2019 But in Washington, Homeland Security Department spokesman Russ Knocke said “the intelligence community has concluded this information to be of doubtful credibility. We shared this information early on with state and local authorities in New York.” Knocke did not elaborate. A counterterror official, who was briefed about the threat by Homeland Security authorities, said the intelligence was considered doubtful because it did not reflect “on-the-ground, detailed” information. Rather, the official, who also insisted on anonymity, said the intelligence was similar to “what can be found on the Internet and a map of New York City.” The law enforcement official in New York said city officials had known about the threat at least since Monday, but held the information until two or three al-Qaida operatives were arrested in Iraq within the past 24 hours. Once the arrests were made, officials felt they could go public, the official said. Authorities are concerned, the official said, that there might be al-Qaida operatives in New York City connected to the plot. They have no hard evidence of that, but are investigating. NEW YORK – Authorities stepped up security Thursday after receiving what city officials called a credible threat that the New York subway could be the target of a terrorist attack in coming days. But Homeland Security officials in Washington downplayed the threat, saying it was of “doubtful credibility.” The threat involved the possibility that terrorists would pack a baby stroller with explosives, among other potential subway bombing methods, a law enforcement official said, speaking on condition of anonymity because the investigation is ongoing. New York officials responded by mobilizing police officers to begin looking through commuters’ strollers, bags, briefcases and luggage. “This is the first time we have had a threat with this level of specificity,” Mayor Michael Bloomberg said at a nationally televised news conference alongside Police Commissioner Raymond Kelly, adding that he still felt secure enough to take the subway home Thursday night. 160Want local news?Sign up for the Localist and stay informed Something went wrong. Please try again.subscribeCongratulations! You’re all set!