A mock movie poster warns al-Qaida wants to return to New York City, but authorities say there's no evidence of an actual threat.
Investigators learned about the online amateur graphic on Monday. The graphic shows the Manhattan skyline at sunset with "Al Qaeda" in bold type followed by "Coming Soon Again in New York."
Al-Qaida has been blamed in the Sept. 11, 2001, terrorist attacks, which destroyed the World Trade Center and killed thousands of people.
New York Police Department spokesman Paul Browne says an overseas, Arab-language Internet site posted the graphic on its "artwork and design" page. He says the NYPD has been monitoring the site.
FBI spokesman J. Peter Donald says the agency takes all threats seriously and "there is no specific or credible threat to New York."