Thousands of fish have died in Swiss sections of the River Rhine as Europe’s heatwave continues.

Swiss authorities say they have pulled a tonne of dead fish from the river and have tried to implement emergency measures to save others.

The rising heat has lowered oxygen levels in the water, making it hard for fish to survive.

Europe is experiencing a prolonged heatwave that has caused wildfires as far north as the Arctic Circle.

The fish most affected is the grayling, which fares better in cooler waters and starts to struggle when the temperatures rises to about 23C (73F).

But temperatures on the Swiss section of the Rhine have risen to more than 25C (77F), and combined with falling water levels it has caused the deaths of thousands of fish.