New York: US law enforcement officials are investigating an image posted on the internet that shows the city's Manhattan skyline at sunset with a warning in the foreground that terror outfit al Qaeda plans to return to New York. The picture came into existance when US announces USD 10 million bounty on Lashkar-e-Taiba (LeT) founder Hafiz Saeed.

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The image, made in the style of a movie poster, was posted on an al Qaeda internet forum. The words 'Al Qaeda coming soon again in New York' are super-imposed on an image of Manhattan's illuminated high-rises.

New York Police Commissioner Raymond Kelly said there is no specific threat to the city at present and the department is investigating whether the message is a credible security threat.

He added the appearance of the image is a reminder that New York remains a top target for terrorist groups.

"There is nothing operational about this (image) but obviously it is cause for concern and it reminds us that New York is very much on their minds," Kelly said in a briefing on Wednesday. He said the police takes any threats to the city seriously.

"Until we learn more about their origins, we take all threats against the city seriously," Deputy Commissioner Paul Browne added. "The NYPD Intelligence Division's cyber unit is investigating the origin and significance of the graphic."

The image was spotted on al Qaeda internet forums on Tuesday even as several other websites linked to the terror group have remained shut down for about a week.

It appeared on a website that has hosted al Qaeda material in the past and is a "Category 1" website, a classification used by NYPD Intelligence Division to describe sites that are heavily used by followers of the terror outfit.

The FBI, in a statement, said there was "no specific or credible threat to New York at the moment. The FBI's "Joint Terrorism Task Force is aware of the posting and investigating its authenticity and origin", the agency said.

Browne told that the police believe the images were not posted by an American. "We're leaning toward an Egyptian, using Arabic, to create communications on this site," he said. Browne identified the site as gulfup.com.

Years after the September 11 attacks, Pakistani-American Faisal Shahzad had made a failed attempt to blow up a car bomb in the city's busy Times Square in May 2010.

(JPN/Agencies)