Police board KLM flight in Cologne 24 to arrest suspects . Two suspects said to be German man , Two and German born in Cologne , early Friday . Terrorism expert Sajjan Gohel told CNN the arrest showed Germany faces a major threat from extremists . Police say `` farewell '' letters found from the men .
Police board KLM flight in Cologne 24 to arrest suspects . Two suspects said to be German man , Two and German born in Cologne , early Friday . Police say `` farewell '' letters found from the men .