BERLIN — Authorities in West Germany say they have arrested an Iranian man on suspicion of planning a deadly chemical attack.

Police and prosecutors said early Sunday that the 32-year-old man and another person were being held in the town of Castrop-Rauxel, northwest of Dortmund.

In a joint statement, they said the man is suspected of planning a serious attack motivated by Islamic extremism, for which he allegedly obtained cyanide and ricin.