The unidentified 23-year-old suspect, a known right-wing extremist of no
fixed address, allegedly incited another man (42) to build the device, said
police and prosecutors.
They did not identify his suspected targets.
Police were also investigating two other suspects, men aged 22 and 24, over
the alleged plan and had raided their homes last week in the southwestern
state of Baden-Württemberg.
The arrested man had previously taken part in a rally of anti-immigrant group Die Rechte (The Right) on August 31st and hurled firecrackers at anti-fascist
counter-demonstrators, injuring five.
A police searched the home of the alleged bomb-maker and found
an explosive device, chemicals, several model aeroplanes, a data storage device
and a video camera.
Police said the 42-year-old man - who the younger suspect recruited to build the plane bomb - from the Emmendingen district had no previous known history of political extremism and that he remained free on bail.
In June, German authorities staged raids after uncovering a similar alleged
plot by Islamists to carry out bomb attacks against state targets using model