The German Police has a list of 548 Islamists who the German authorities believe they pose a threat to the national security.
Among them are at least 50 Islamists whose asylum application has been rejected but they have not been deported.
According to German media, the number of the Islamists in German prisons have increased by 30% last year to over 150.
This is not the only unexplained blunder of the German authorities. Just a few days ago, it was revealed that the police knew of 14 identities being used by Berlin truck killer Anis Amri almost a year before his attack.
One of his roommates had even informed the police in 2015 of Amri’s connections with the Islamic State. On March 2016, the authorities had received a tip about a meeting Amri would have with an unknown supporter of ISIS because he wanted to “kill in the name of Allah”.