PRAHOVO, Serbia (AP) — Water levels on the Danube River, the second longest in Europe, have dropped so low because of drought that the hulks of dozens of World War II German battleships are emerging into view.

They are a curious distraction from the summer heat crisis. The Danube’s record low water levels also have forced power plants to the brink of shutting down, and governments across Central and Eastern Europe are taking steps to conserve electricity.

In the middle of the river separating Serbia and Romania near the Serbian port of Prahovo, a rusty hull is now visible along with a broken mast where the Nazi flag used to fly.

The ships, some still laden with weapons, belonged to Nazi Germany’s Black Sea fleet that the Germans deliberately sank as they retreated from Romania and as Soviet forces advanced deeper into Europe near the end of the war.

Historians say up to 200 German warships were scuttled in September 1944 near Prahovo in the Danube gorge as they came under Soviet fire. The idea behind the deliberate sinking was to slow down the Soviet advance in the Balkans. But Nazi Germany surrendered months later, in May 1945.

The sight of the old warships is a reminder that the Serbian government, with European Union financial support, has long been trying to do something about them. Some were removed from the river by Communist Yugoslav authorities, but most have remained because of the explosives they carried.

Now, however, authorities are trying to keep traffic flowing on the Danube, which flows through 10 nations, as the dropping water levels create dangerous conditions. Experts have linked the unusually hot weather to global warming and other factors.

Krsta Brandic, a Prahovo resident, said the low water levels have almost stopped ship traffic: “As you can see, the (big) ships can’t pass anymore."