German police have arrested a 32-year-old Iranian national suspected of acquiring the deadly poisons cyanide and ricin to commit an “Islamist-motivated” attack, authorities in western Germany said on Sunday.

The suspect’s residence in the city of Castrop-Rauxel was searched as part of the investigation, according to a joint press release from the Dusseldorf prosecutor’s office and police in the cities of Recklinghausen and Muenster.

Police said the Iranian was suspected of planning a “serious act of violence endangering the state” by allegedly acquiring cyanide and ricin to commit an Islamist-motivated attack. This carries a prison sentence of between 6 months and 10 years.

“Germany remains a direct target of Islamist terrorist organizations. Lonely, Islamistically motivated perpetrators are another considerable danger,” German Interior Minister Nancy Faeser said after news of the investigation broke.

“That is why our security authorities expect an attack to be prepared at any time,” he said, adding that since 2000 German security authorities had prevented 21 Islamist attacks in Germany.

Police seized electronic storage devices but found neither cyanide nor ricin during the search at Castrop-Rauxel, Holger Heming of the Dusseldorf prosecutor’s office told Reuters TV.

Police said a second person was detained as part of the searches, adding that a decision on whether to issue an official arrest warrant would be made at a later date as the investigation continues.