The Ministry of the Environment of the German state of Brandenburg reported that an unknown highly toxic substance was found in the Oder River, which flows through the territory of Poland and Germany, causing mass death of fish.
The ministry explained that the analysis of river water showed the presence of synthetic chemicals of unknown origin, which can have toxic effects on vertebrates, indicating that it is not yet possible to determine the number of dead fish in Poland and Germany.
German authorities in Uckermark and Barnim, where hills and a nature reserve are located, have advised people to avoid contact with the waters of the Oder River and the adjacent canal.