Germany's domestic security service has warned the country's Jewish community and the Israeli embassy of an increased danger of terrorist attack. The threat appears to emanate from Lebanon.

The general secretary of the Central Council of German Jews, Stephan Kramer, has confirmed weekend news reports that increased precautions were being taken Germany-wide. However, he also warned against scaremongering.

Kramer told daily Berliner Zeitung that the Council had been approached ten days ago by the German security authority, the BKA, following the arrest of a suspected Al Qaeda member in Lebanon.

Security measures reinforced

Bildunterschrift: Großansicht des Bildes mit der Bildunterschrift:  Police patrols are routine outside many Jewish insitutions in Germany

Police have also been warned to be more vigilant. In Berlin, police are increasing the number of units deployed to guard buildings linked with the Jewish community. 

Four Arab men were arrested while acting suspiciously near Jewish institutions in Berlin on Saturday, Jan. 19. Three of them have subsequently been released because of insufficient evidence. The fourth is being held for unrelated offences.

Concrete blocks are reportedly set to be erected outside a least three buildings in the capital this week, including the city's Jewish Museum and a major synagogue. The additional security measures are designed to stop attacks with vehicles.

Kramer referred to information from Lebanon and a possible link to the current trial in Dusseldorf of a Lebanese man, Youssef al-Hajj Dib, 23, on charges of attempting to blow up two German trains with suitcase bombs in July 2006.

German authorities have declined to comment on the reports, which came just days after another terror alert about a possible attack on the German justice ministry was downgraded.