"Anti-Semitism and hostility towards Israel are the connecting elements among Islamists, German and Turkish left- and right-extremists and people belonging to extremist Palestinian organisations," said the agency's president, Thomas Haldenwang.
"The common concept of Israel as an enemy creates old and new connections between some of these players that in the future could lead in some cases to stronger cooperation," he added.
However, the left-wing and right-wing extremist scenes are internally divided between pro-Israeli and pro-Palestinian positions, with some right-wing extremists using the current situation to agitate against Muslims and migrants, according to the agency.
Security authorities are facing parallel crises and threat situations that have been intensified by Hamas' Oct. 7 attack on Israel and the subsequent fighting, according to Haldenwang.
He spoke of a new quality to threats by Islamists to carry out attacks in the West that has recently emerged.
"The danger is real and higher than it has been for a long time," said Haldenwang.
Security authorities are working "at full speed" to ensure the safety of Jewish people and Israeli institutions, as well as major events, he added.
(Reporting by Andreas Rinke and Alexander Ratz, Writing by Linda Pasquini and Miranda Murray, editing by Alexandra Hudson)
