Cleanup operations have begun in parts of Serbia and Bosnia after massive floods, even as cities on the Sava River brace for a new wave of flooding.
Thousands of people were evacuated in both countries.
Serbian Prime Minister Aleksandar Vucic said 44 people were reported killed -- 16 in Serbia, 27 in Bosnia, and one in Croatia.
Authorities are now concerned that higher temperatures, thousands of animal carcasses, and polluted water may lead to outbreaks of disease.
River levels were still rising in the Serbian capital, Belgrade, and further west toward the Bosnian border.
In Bosnia, where one-third of the country is dealing with flood conditions, some 300 mudslides have been reported, mostly in the northeast.
Officials in Bosnia are also concerned that the flooding will unearth some of the landmines left over from the 1992-95 war and that minefield warning signs will be washed away.
PHOTO GALLERY: Thousands of people have fled their homes amid massive floods in Serbia and Bosnia-Herzegovina.
An aerial view shows the town of Brcko in northern Bosnia-Herzegovina on May 18.
A man stands on a roof in Pozega, Serbia.
Residents of the town of Obrenovac, east of Belgrade, wait for evacuation assistance.
A rescue effort in Obrenovac, Serbia
Residents of Gunja, eastern Croatia, ride a boat through flooded streets.
Sunken vehicles in the flooded village of Gunja, eastern Croatia
A rescue team looks for residents in need of help evacuating the town of Obrenovac, Serbia.
An aerial view of a flooded suburb of Sarajevo, Bosnia-Herzegovina
Heavy equipment helps residents evacuate their flooded houses in Topcic Polje, Bosnia-Herzegovina.
Serbian soldiers help a man out of his flooded house in the town of Obrenovac, Serbia.
A vehicle is buried in mud in Topcic Polje, Bosnia-Herzegovina.
A woman attempts to save furniture from her flooded office in Banja Luka, western Bosnia-Herzegovina.
Evacuees from the Serbian town of Obrenovac take shelter at a hall in Belgrade.
An elderly woman from the town of Obrenovac at a shelter for flood victims in Belgrade
Sand bags line the banks of the Sava River in the Serbian city of Sremska Mitrovica.
Based on reporting by Reuters, Interfax, AFP, and AP