Hundreds of thousands of people have been left without heating and hot water after Russia halted gas supplies to the region on Jan. 1, over an alleged $709 million debt for past supplies.

More than 51,000 households were left without gas and 1,500 apartment buildings had no winter heat in Moldova's pro-Russian separatist enclave, authorities said on Monday, as Moldova and Russia traded blame for an escalating energy crisis.

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.

Russia denies using gas as a weapon to coerce Moldova, and blames Kyiv for refusing to renew a gas-transit deal.

Moscow breakaway region of Transnistria halted almost all industrial activity except for food production, following the end of Russian gas flows through Ukraine, Interfax reported.

Moldova has accused Russia of triggering an energy crisis after tens of thousands of homes in its eastern breakaway region of Transnistria were left without heating, gas or electricity following the end of a Ukraine gas transit agreement last week.