New York (CNN) -- Gotham's top cop on Tuesday said authorities are looking into the possibility that an Egyptian writer may have been responsible for an online posting that pictured a New York cityscape with the words "Al Qaeda. Coming Soon Again in New York." "The use of language indicated that," said New York Police Commissioner Ray Kelly. "Its many different dialects in Arabic and our analysts thought that this was Egyptian in nature." He said that the graphic image, which surfaced Monday on a few jihadist Web forums and featured the words in the English, did not coincide with any specific online chatter about a potential threat and that it was unclear whether one or multiple individuals was responsible for the posting.
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NEW: NYC Police Commissioner Ray Kelly said that threat may be "Egyptian in nature"
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Image shows NYC cityscape with words "Al Qaeda. Coming Soon Again in New York"
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The FBI says "there is no specific or credible threat to New York at this time"
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The FBI and the NYPD are investigating the origins of an online posting
"Until more is learned about their origin, we take all threats against @placeholder seriously."