Former Al Qaeda leader Osama bin Laden
Former Al Qaeda leader Osama bin LadenIsrael news photo: Flash 90

Authorities in New York and Berlin are investigating threats made by on websites associated with Islamist radicals that posted threats this week, promising to conduct attacks in both cities. Officials in New York said that it was possible that the threats were genuine, although they were also investigating the possibility that the threats were a prank.

Meanwhile, In Berlin, officials said that the threats probably did emanate from Al-Qaeda associated groups, who are demanding the release of a terrorist being held in a German prison.

The New York threat was detected by authorities on a website used by Islamists to communicate. The threat comes in the form of a “movie poster,” showing New York's famous skyline at sunset. Emblazoned on the forefront of the post is the text “Al Qaeda: Coming Soon Again in New York.”

The FBI is investigating the threat. In a statement, the Joint Terrorism Task Force said that there was “no specific or credible threat to New York” at this time. A spokesperson for the New York Police said that city officials were investigating as well. However, he said, the poster was included in a section of the Ansar al Mujahiddin Arabic Forum dedicated to art and design - “not where an important threat would be posted.” Nevertheless, he added, every scenario was being taken into consideration.

Meanwhile, officials in Berlin were investigating a threat posted online in the name of Al Qaeda, claiming that the terror group would strike at the “heart of Berlin” unless a jailed female terrorist was released. "This is a special message to the old lady of Germany (Chancellor Angela) Merkel... you should learn from what happened in France," the unsigned statement said. "Immediately release Um Seif Al-Islam Al-Ansariya before another Mohammed Merah strikes at the heart of Berlin," it added, referring to the attack in Toulouse, France several weeks ago.

Um Seif Al-Islam Al-Ansariya, whom the message demands Berlin release, is also known as Felis Lowitz, who was convicted several years ago of plotting to blow up the Rammstein military base in Germany, used by U.S. troops.