The comments by Mr. Hanning , a former head of the federal intelligence service , underscore why this case is viewed as the gravest terrorist threat in Germany since 2001 , when militant Islamic students living in Hamburg laid the plan to hijack commercial airliners in the United States .
Hamburg
Germany
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Germany
Hamburg
/location/location/contains
Germany
Hamburg
/location/country/administrative_divisions
LOCATION
Germany
LOCATION
Hamburg
LOCATION
United States