The head of Moldova’s breakaway region Transnistria has urged residents to burn firewood for heating and warned that blackouts cannot be avoided, after Moscow stopped supplying gas via Ukraine.

Moldova faces a security crisis, Prime Minister Dorin Recean said on Friday after its separatist pro-Moscow Transdniestria region, cut off from supplies of Russian gas, closed factories, restricted central heating and imposed rolling power blackouts.

Russia’s state-owned energy giant Gazprom says it will halt gas supplies to Moldova starting on Jan. 1, citing alleged unpaid debt by the east European country.