"The Otradnaya meteo station has today recorded a temperature of minus 28.2 Celsius in the southeast of the Krasnodar region, (and) minus 20.1 Celsius at Dzhubga on the Black Sea," said the Russian Hydrometeorological Research Centre.

Temperatures at the resort town of Anapa plunged to between minus 15 and minus 18 Celsius, it said in a statement. Winter temperatures on the palm-dotted Black Sea coast rarely fall below zero.

"Historic winter records have been broken in Russia's south," added the Moscow-based Fobos weather forecaster.

"Comparing the records with climate extremes you realise that this has not happened before, (or) at least for the last 100-120 years," said Fobos, suggesting the extreme cold could affect the fruit harvest.

The bitter cold has claimed 110 lives across Russia since the start of the year, according to the health ministry.

Bulgaria halts electricity exports amid cold snap
Sofia (AFP) Feb 9, 2012 - Bulgaria is to halt electricity exports over its inability to guarantee local consumption in the cold spell gripping the country this week, the economy and energy ministry said Thursday.

"Due to persisting heavy winter conditions in the country we will stop electricity exports as of 1:00 am Friday (2300 GMT Thursday)," the ministry said in a statement.

"The decision is necessitated by the shortage of about 400 megawatts per hour for the local market," it added.

Bulgaria exports an average 1,000 megawatts of electricity per hour to neighbouring Greece, Serbia, Macedonia and Turkey.

But the ministry said it had already switched on all its reserve capacities to cover increased domestic demand as temperatures dipped to minus 28.6 degrees Celsius (-19.5 Fahrenheit) in the northwestern town of Vidin early Thursday.

The situation was aggraveted by problems with production at the US-owned AES Galabovo coal-fired plant in southern Bulgaria, it added without elaborating.

Severe flooding had disrupted coal supplies to all four plants in the Maritza East complex near Galabovo this week as miners could not get down to work in the three open pit mines in the region.

"Electricity exports will resume when we recover the reserves necessary to guarantee safe and uninterrupted home supply," the ministry said Thursday.

Bulgaria is a key electricity exporter on the Balkans sending abroad 10.5 billion kilowatt hours last year.

The 2,860-kilometre (1,780-mile) river, which flows through 10 countries and is vital for transport, power, irrigation, industry and fishing, was wholly or partially blocked from Austria to its mouth on the Black Sea.

With ice floes in the river around Belgrade up to half a metre (1.7 feet) thick, the Belgrade port authority said that all vessels on the 600-kilometre stretch through Serbia were safely in port.

A government ban on navigation on all the country's waterways was expected to remain in place for some 10 days, deputy infrastructure minister Pavle Galic told the Beta news agency.

Officials in Serbia and Croatia said they could not yet oversee the economic effects of the shipping ban on the Danube.

"It is too soon to tell but it could be very bad," an official from the Serbian economy ministry told AFP.

Upstream in Croatia an rescue operation was underway to help the three-member crew of a Croatian vessel trapped in the ice near the main Danube port of Vukovar since Friday and running out of food, port official Ivan Barovic said.

All shipping has been halted since Wednesday on the 137 kilometres (85 miles) of the Danube flowing through Croatia, Barovic told AFP.

Serbian railways meanwhile said Thursday that the famed Balkan Express train that runs from Belgrade to Istanbul would only go as far as Sofia for the time being because of flooding in Bulgaria related to the cold snap.

Top Serbian water official Aleksandar Prodanovic said he hoped for a slow thaw by some five degrees Celsius daily "so the snow melts slowly and causes no bigger problems."

A quick rise in temperature could trigger floods because of the high levels of snow in Serbia which is up to 1.5 metres in some parts, he told Radio Belgrade.

Serbian President Boris Tadic also stressed preventive measures must be taken to deal with possible land slides and floods triggered by melting snow in the coming weeks, Tanjug news agency reported.

Tajic was speaking on a visit to western Serbia to visit villages affected by the ongoing cold snap which has cut off some 70,000 people from the outside world in the region.

Bulgarian authorities, who have also banned all navigation on the river, reported the Danube frozen between 50 and 90 percent, while a total of 224 vessels were stuck in six ports and a river channel in Bulgaria.

In Romania the river was completely frozen along a 120-kilometre stretch between Moldova Veche and Turnu Severin at the Serbian end, and a further 117 kilometres downstream between Calarasi and Harsova, as well as at Isakcha, in the Danube delta.

Upstream in Hungary ships were still being allowed on the Danube but "at their own risk" the authorities said, adding that ice was covering between 60 and 70 percent of the river

But in Austria navigation was impossible as the river had an ice layer up to 12 centimetres (4.7 inches) thick in parts.

"For the Danube to freeze we need temperatures of under minus 10 Celsius (14 Fahrenheit) for at least a week. That is currently the case," the river traffic body Via Donau said.