Dozens of German warships sunk during World War II have resurfaced in the Danube River in eastern Serbia amid Europe’s worst drought in years, according to a Friday report.

The Reuters news agency reported that the Danube was at its lowest levels in almost a century. Hundreds of ships belonging to Nazi Germany’s Black Sea fleet were sunk in the river as they retreated from advancing Soviet forces in 1944, and still hamper traffic when water levels are low.

More than 20 ships have been exposed, still containing ammunition and explosives, along a stretch of the river near Serbia’s river port town of Prahovo, Reuters reported.

The explosive-laden ships pose a danger to shipping routes and Serbia’s and Romania’s local fishing industry.

According to Reuters, some of the exposed ships have narrowed the navigable section of the river near Prahovo from 180 meters to 100 meters (590 to 330 feet).

“The German flotilla has left behind a big ecological disaster that threatens us, people of Prahovo,” Velimir Trajilovic, 74, a local who wrote a book about the ships, told Reuters.

The severe decline of the #Danube River to its lowest level in almost a century reveals the hulls of dozens of #German warships that sank during #WWII near the Serbian port of #Prahovo overlooking the river that passes and borders 10 European countries. pic.twitter.com/iHGNOtZ4Q0

— خالد اسكيف (@khalediskef) August 20, 2022

The news agency said that in March, the Serbian government held a tender to salvage the ships and remove the ammunition and explosives. The cost of the operation was estimated at $30 million, the report said.

Europe has been facing record-high temperatures in recent months, leading to risks of droughts across the region.