A new calamity emerged Tuesday in the flood-hit Balkans even as emergency workers battled overflowing rivers and evacuated thousands: tons of drowned livestock were posing a health hazard.
With the rainfall stopping and temperatures rising, the withdrawing floodwaters revealed a harrowing sight: thousands of dead cows, pigs, sheep, dogs and other animals that were left behind after their panicked owners fled rapidly advancing torrents.
"There are tons of dead animals that we must dispose of," Serbian Prime Minister Aleksandar Vucic told a government meeting Tuesday.
One farm near the northern Bosnian town of Samac reported losing 450 of its 500 cows.
The record flooding in Serbia, Bosnia and Croatia in past week has forced half a million people out of their homes and led to at least 40 deaths: 20 in Serbia, 18 in Bosnia and two in Croatia. Authorities say the death toll still could go higher.
Bosnia declared Tuesday a day of mourning while Serbia said it would hold three days of mourning for flood victims from Wednesday to Friday.
Witnesses say the waters in some areas rose within hours, racing into yards and homes without warning and flooding entire towns. In many cases, farmers did not have time to unleash their livestock or let them out of barns to try to swim to safety. Only some were pulled out in time.
Authorities in Bosnia have asked for international help to deal with the animal carcass problem, while governments in both Serbia and Bosnia have set up special phone lines for people to reach sanitary teams to pick up dead animals.
Serbian state television on Tuesday showed army teams spreading out to decontaminate and disinfect flooded areas to prevent possible diseases.
Residents also have been given special sanitary instructions: they are not to return to their homes before disinfection and not to eat any food from flooded gardens, orchards or barns.
"Dead animals are a special problem. Those have to be removed and destroyed properly or at least dug deep into the ground and covered with calcium oxide," said Bosnia's chief epidemiologist, Dr. Zeljko Ler.
Several swollen livestock could be seen along the roads leading toward Serbia's hard-hit town of Obrenovac, outside the capital of Belgrade. The animal carcasses were apparently brought over from fields and barns for veterinary teams to pick up.
In Obrenovac itself, dozens of stray dogs and others abandoned by fleeing owners were roaming the town's muddy streets, looking for food among the scattered debris.
Ler warned that acute stomach ailments and other diseases — including hepatitis and typhoid — often occur in the aftermath of the flooding.
"We are warning the population to drink only boiled or bottled water," he said. "There are still no mass infections (yet) but for some diseases the incubation period is 14 to 21 days."
In neighboring Croatia, authorities said they managed to save 7,500 livestock from eastern flooded areas and transport them to safety.
The floods are still threatening Serbia's biggest power plant, located in Obrenovac, while in Bosnia, many areas faced new land mine dangers after hundreds of landslides hit, shifting mine fields left over from the country's war.
Water levels in the mighty Danube were also rising Tuesday and Serbian authorities ordered the evacuation of two villages along the banks of Europe's second-largest river.
Both Serbia and Bosnia have appealed for international help, saying damage from the flooding will be measured in billions. The two countries still have not fully recovered from wars of 1990s, which claimed 100,000 lives and left millions homeless.