Poland has put up a dam to catch all the dead fish that are flowing down from the Czech side of the River Odra, a local official has said.
Media and politicians in Germany are using disinformation tactics in news stories about the pollution situation on the River Odra, the Polish information security chief has said.
With climate change meaning hotter summers and low levels of water in one of Poland's biggest rivers, experts say that it was only a matter of time before something happened.
A total of 134 tonnes of dead fish, recovered from the River Odra, have already been disposed of, the Zachodniopomorskie provincial governor has said.
Through the use of satellite images, German scientists have confirmed a massive algal bloom in the River Odra, in which an unknown pollutant has led to mass deaths of fish, the RND website reported on Monday.