Russian cargo planes carrying boats, generators and food have joined rescue teams from around Europe and thousands of local volunteers to evacuate people and build flood defences after the River Sava in Serbia burst its banks following days of torrential rain.
Flood waters receded on Sunday in some of the worst-hit areas of Serbia and Bosnia, but the Sava was forecast to rise further after thousands of people were displaced by rising waters.
Flooding has already cut Serbian power generation by 40 per cent, forcing the cash-strapped country to boost imports.
Soldiers, police and villagers have battled to protect power plants in Serbia from rising flood waters as the death toll from the Balkan region's worst rainfall in more than a century reached 37.
Twelve bodies were recovered from the worst-hit Serbian town of Obrenovac, which lies 18 miles south west of the capital, Belgrade, but the number was likely to rise as waters receded.
Serbian Prime Minister Aleksandar Vucic admitted to reporters the situation is "catastrophic".
The worst flooding since records began has killed at least 20 people dead in Serbia and Bosnia and has forced tens of thousands to flee their homes.
The flooding is the worst since records began 120 years ago, according to meteorologists, who said it is due to the region getting three months of rain in just three days.
Dramatic footage from Belgrade has shown a mother and baby being airlifted from a house after floods ravaged parts of Serbia and neighbouring Bosnia.
Thousands of people in the Balkans have been evacuated from their homes over the past few days as the region was hit by the heaviest rainfall since measuring started 120 years ago.
The Associated Press news agency, which provided the video, reports that an estimated 20 people have died in Bosnia and Serbia as a result of the flooding.
Nationwide emergency measures were declared after rain-swollen rivers have flooded roads, cut off power and caused more than 200 landslides.
William Hague has hailed Bosnia's decision to include prevention of sexual violence in military training.
The Foreign Secretary told a conference in Bosnia's capital Sarajevo that rape is a "cheap" and "devastatingly effective way to terrorise and displace a population".
Hollywood star Angelina Jolie called Bosnia's decision to include prevention of sexual violence in military training "inspiring" and "groundbreaking".
Speaking at a conference in the Bosnian capital Sarajevo, the UNHCR goodwill ambassador said the issue of war zone rape "has been a taboo subject in all countries".
"You are helping to break down those taboos and [are] redefining soldiering in the 21st Century," she told the audience.
"There can be no peace in conflict or post-conflict zones while women are raped with impunity," the actress added.
Actress Angelina Jolie, in her role as UNHCR goodwill ambassador, and Foreign Secretary William Hague met Bosnia's presidency to discuss the prevention of sexual violence in conflict.
The city of Homs in Syria has the potential to see a massacre like the one in Srebrenica in 1995 the Foreign Secretary has warned.
William Hague said that while it was a welcome move that women and children were being allowed to leave the area he said: "I think there should be a real fear." Adding that there was a question over "what will happen to the men and the boys that are left?"
The war in Bosnia saw Europe's worst mass killing since the Holocaust as around 8,000 Muslim men and boys were killed by the Bosnian Serb forces.
More than 150 bodies have been recovered from a mass grave found in Tomasica near Prijedor in northern Bosnia and Herzegovina, more than 20 years after the war which claimed the lives of more than 11,500 people.
The latest mass grave to be uncovered was believed to have contained 1,000 bodies when it was originally dug in the summer of 1992, but it is thought some may have been moved to another mass burial site and it will take months of digging to establish how many bodies remain at Tomasica.
The war in Bosnia saw Europe's worst mass killing since the Holocaust during World War Two as around 8,000 Muslim men and boys were killed by the Bosnian Serb forces, many died in detention camps.
The conflict also saw the longest siege in modern history. The Serb siege of Sarajevo went on for 44 months - 11,825 days - longer than the World War II siege of Leningrad, now St. Petersburg, Russia.
As forensic teams continue to uncover bodies in a mass grave in northern Bosnia, one woman has said that she is still waiting for the bodies of her brother and husband.
Nasiha Klipic told ITV News: "I have come to this cemetery for many years and I see each and every one of these buried people as my brothers – as my family.
"But I would feel a lot better if my brother and my husband finally found their final resting place here."
However, she said that even if the bodies of her relatives were found she would not rest until all those responsible were held to account.
"It would not be the end for me, the end for me would be when all the war criminals are arrested.
"I will not stop until the day I die and I raise my children not to stop until the day they die, until all the war criminals are arrested. Nothing less than that would be the end for me."
It is hoped further evidence found at the huge grave site could help the trials of Ratko Mladic and Radovan Karadzic, who are currently facing charged at The Hague.