BERLIN, July 30 (Xinhua) -- Unknown chemicals were released in a subway station in the western German city of Dusseldorf on Wednesday, German local media reported.
The underground station Heinrich-Heine-Allee has been evacuated and closed.
According to a fire department spokesman, an adhesive reacted with another emitting smoke and an acrid smell.
Authorities have conducted air sampling and analysis. It is still not known why the adhesive caused a chemical reaction, report said.