Italy has imposed emergency measures on businesses to conserve gas supplies as freezing weather continues to grip the country and much of Europe.
An "emergency situation" is in place in southern Serbia where 70,000 villagers are stranded by snow.
In Greece, several villages near the Bulgarian border have been evacuated after the River Evros burst its banks.
A day of mourning has been declared in Bulgaria, where a dam collapsed leaving nine people dead,
A 2.5m (8ft) torrent surged through the south-eastern village of Biser on Monday. Five people were killed in the village itself and four more died elsewhere when their cars were swept away by the flood.
Two more dams were said to be on the brink of collapse and officials declared a code orange for much of the country, a severe warning of the risks of damage or injury from the harsh wintry conditions.
In Greece, a state of emergency was declared in the Evros region.
The authorities also said a 40-year-old British woman was drowned in a flash flood on the Aegean island of Symi.
And there was a threat of flooding from the Danube and Ibar rivers in Serbia, where the army was planning to use explosives to break up the ice.
In Italy, snow and ice have brought many public services to a standstill. Temperatures fell as low as -10C in the south and -21C in the north on Tuesday.
Two further deaths were reported and several major roads were blocked.
A woman was found dead early on Tuesday, apparently due to hypothermia, and a man, 86, died after slipping on ice.
More than 25 people have died over the past few days in rare conditions that have seen almost all of Italy blanketed in snow.
The army was brought in to help hundreds of people who were said to have spent Monday night stranded on a road near the southern town of Candela, in Puglia.
Government and industry officials were set to discuss a "critical" energy situation.
Italy imports most of its energy and while gas consumption has soared, supplies from Russia have been reduced.
EU officials deny there is an emergency caused by a drop in gas from Russia but Italian energy company Eni says supplies into Italy are down by 20%.
Russian gas giant Gazprom - which supplies about a quarter of Europe's natural gas - says it is facing greater domestic demand because of the extreme cold.
The Italian government has reassured the public that they will not face cold homes but Eni has spoken of a "difficult moment" and the head of Italy's business organisation, Emma Marcegaglia, said she was "preoccupied" with the situation and with the cuts to supplies faced by businesses.
Some power stations will switch to oil and some industrial customers will have gas supplies cut so homes stay warm.
However, Eni urged private consumers to cut back on energy use as much as possible.
Chief executive Paolo Scaroni said: "We are in an emergency and we have reacted to this emergency by increasing gas imports from Algeria and from northern Europe via Switzerland.
"We won't have problems until Wednesday," he said on news channel Radio 24.
Many of the victims of Europe's cold snap have been homeless people in Ukraine and Poland.
Forecasters says the icy conditions will last at least until the end of this week.