In a mass die-off, thousands of dead fish are showing up along the Oder River that runs between Poland and Germany.
Laboratory tests done on river samples in both countries have detected high levels of salinity but no mercury poisioning has been found so far. Comprehensive toxicology studies are, however, still under way in Poland, reported Al Jazeera.
The German government has flagged an environmental catastrophe and advised people to avoid the river, reported BBC.
Meanwhile, authorities in both countries have been reportedly accused by environmental activists of failing to work together to resolve the issue.
On Friday, Polish Prime Minister Mateusz Morawiecki sacked a pair of environmental officials over their handling of the incident, reported BBC.
He also attributed the phenomenon to the dumping of huge amounts of chemical waste into the river causing 'environmental damage so severe it would take years for the waterway to recover.'
The Oder River runs from the Czech Republic to the border between Poland and Germany before flowing into the Baltic Sea.
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