The President of Belarus, Alexander Lukashenko, has reacted angrily to a Russian decision to cut gas supplies to Belarus.
By Steve Rosenberg
BBC Moscow correspondent
He accused Moscow of "terrorism" and warned that relations between the two countries could suffer long term damage.
Escalating the dispute into a diplomatic war, Mr Lukashenko, accused Russia of "terrorism at the highest level", for leaving his country freezing in temperatures of -20C.
President Lukashenko accused Russia of "terrorism" for cutting gas
He said relations with Russia would now be poisoned for a long time.
Earlier, in the capital, Minsk, a government statement suggested there had not been such unprecedented steps to deprive people of gas in the winter since World War II.
Russia claims its row with Belarus is purely financial.
Minsk, it says, has stopped paying for subsidised Russian gas and has even been siphoning off supplies bound for Western Europe.
Which is why the Russian gas giant, Gazprom, has now turned off the taps.
Belarus has accused Russia of "blackmail": of cutting off supplies so that Russia can buy control of the pipeline which carries gas through Belarus to Western markets.
But it is not just Belarus which is beginning to freeze.
The Russian region of Kaliningrad, too, is now short of heat - it receives its gas through the same pipeline.