Ivan Kulychenko said Ukraine's third largest city, with a population of more than 1 million, was left almost with no heating supplies on Tuesday.
Gas distribution companies claimed they were unable to buy gas for the city due to household debts, but Kulychenko said the city had paid in full for gas supplies to the public sector and therefore, cuts in heating supplies to schools, hospitals and other budget-maintained institutions were unlawful.
Nevertheless, the mayor urged city residents to settle their gas and heating arrears.
A similar situation occurred in December 2008 in the country's capital, Kiev: Due to a conflict between Naftogaz and Kievenergo, a local energy company, the city was left without hot water and heating for about a week.
The conflict was eventually resolved, but Kiev has yet to settle its gas debt.