Russia's defence ministry rebutted Ukraine's claim it was behind the attack, saying its forces "did not plan or carry out strikes using missiles or air strikes within the city limits of Kharkiv."
Demonstrations have now affected 20 areas, mostly towns in the west of the country, according to an AFP tally of official and local Iranian media reports.
The flames spread with terrifying speed in the bar, in the Swiss luxury ski resort town Crans-Montana, which was packed with New Year's Eve partygoers.