At least 43 people have died in the past five days in Ukraine in a cold snap that has brought temperatures down to minus 33 degrees Celsius, causing chaos across swathes of southern and eastern Europe.
Most of the victims were homeless people killed by hypothermia, Ukraine's emergencies ministries said as the country reeled from its coldest winter in six years.
Temperatures in the eastern European nation do not normally drop below minus 15C in winter.
Another 500 people have been treated in hospital for frostbite and other cold-related ailments while 1,600 centres have been set up to provide makeshift accommodation and dispense food and drinks for homeless people, the ministry said.
In the Black Sea, Turkish coast guards are searching for eight crew members missing since a cargo ship sank in stormy conditions near the port of Zonguldak on Tuesday.
The Cambodian-registered Vera was sailing from Russia to the Turkish Aegean port of Aliaga, according to Turkish media..
Three members of the 11-strong crew, consisting of 10 Ukrainians and a Georgian, were saved and taken to hospital.
Also in Turkey, the Bosphorus Strait, a key shipping route for Russian oil and other commodities, was closed to all vessels on Tuesday due to reduced visibility caused by a snowstorm, coast guard officials said.
Passage for vessels longer than 200 metres and those carrying dangerous cargo was suspended on Monday due to poor visibility in the strait, which runs through Istanbul and forms a vital link for traffic between the Black Sea and the Mediterranean.
Seven north-bound and south-bound tankers were waiting for the Bosphorus to re-open, shipping agenct GAC said.
There were gale warnings for parts of the Marmara, Black Sea and Aegean, the shipping agent added.
Russia reducing gas to Europe
Meanwhile, Russian gas giant Gazprom said it ahd restricted supplies to Europe, its largest foreign market, to cover an increase in domestic demand caused by the cold snap.
Supplies into Italy via the Austrian border, had been reduced by 10 per cent compared with normal levels, the European Commission said on Tuesday, quoting Italian officials.
The European Commission said it had enough natural gas to make up for any shortfall and was confident demand could be met.
"(EU) member states are currently able to cover the Russian missing volumes with gas from underground storage and
alternative routes and suppliers," said Marlene Holzner, a commission spokeswoman.
"Given the surplus of gas in the European markets in the previous weeks, the Commission is confident that the market is able to allocate gas where it is most needed."
Large parts of Russia have been hit by what weather forecasters have called "anomalous cold", with temperatures in
the Moscow region falling to minus 15-22C during the day and minus 22-29C at night.
Temperatures are expected to remain well below normal over the next 10 days, forecasters say, with temperatures averaging minus 20C in Moscow.