Thick ice has closed hundreds of kilometers of the Danube River in several countries and confined scores of ships to port on Europe's busiest waterway.
The 2,860-kilometer river, which flows through nine countries, was wholly or partially blocked on February 9 from Austria to its mouth on the Black Sea.
All vessels on the 600-kilometer stretch through Serbia were blocked in port.
In Romania, the river was completely frozen along two stretches of more than 100 kilometers each.
Serbia and Romania have expressed fears that ice formed on the river could jeopardize power production at hydroelectric plants. Romania and Serbia share the Iron Gates hydroelectric power station on the Danube.
In southern Ukraine, ice over the Kerch Strait which links the Sea of Azov to the Black Sea has trapped 126 boats.
Compiled from agency reports