A 32-year-old Iranian man has been arrested in Germany on suspicion of planning an attack with deadly chemicals, officials said Sunday.

Police and prosecutors said the man and another person were detained overnight in the town of Castrop-Rauxel, northwest of Dortmund.

In a joint statement they said the man is suspected to have planned a serious attack motivated by Islamic extremism, for which he had allegedly obtained the potent toxins cyanide and ricin.

German news agency dpa reported that specialists wearing anti-contamination suits carried evidence out of the man’s home.

It wasn’t immediately clear how far advanced the plans for an attack were and whether the suspect had picked a specific target.

But dpa quoted the top security official for North Rhine-Westphalia state, Herbert Reul, as saying authorities had received “a serious tip that led police to intervene the same night.”

Tabloid newspaper Bild reported that the tip about the alleged plans for a chemical attack came from an allied intelligence agency.

Five years ago, German police arrested a Tunisian man and his wife on suspicion of planning to carry out a ricin attack in the name of the Islamic State group. They were later found guilty and sentenced to 10 and eight years’ imprisonment, respectively.