Hungarian authorities have suspended shipping on the Danube because of the risk from floating ice, according to Reuters.
This video shows chunks of ice formed along Budapest.
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See also: Severe weather warnings as UK faces thundersnow and blizzards
The Danube also iced over further downstream near Silistra, Bulgaria.
At least 73 people died during a recent period cold weather that has sent temperatures plunging across southern and eastern Europe, according to the Associated Press.
A combination of the river's shallow waters and the ice makes sailing on the river very dangerous for boats.
Temperatures across Europe are dropping this week and there has even been snow forecast across the UK.
The Met Office have issue yellow warnings for the wind and snow that are expected to hit the country towards the end of the week with up to 20cm to fall in some places.