Russian gas producer Gazprom said on Saturday it had stopped supplying neighbouring Latvia with gas, accusing it of violating conditions for gas withdrawal.
Russia has already cut off gas supplies to Poland, Bulgaria, Finland, Netherlands and Denmark, which refused to pay for gas in line with an order by President Vladimir Putin requiring rouble accounts to be set up in a Russian bank as part of new settlement scheme.
Russia has also halted gas sales to Shell Energy Europe in Germany.
In a statement on Saturday, Gazprom did not specify which gas withdrawal conditions Latvia had allegedly violated.
Gazprom's move comes a day after Latvian energy firm Latvijas Gaze said it was buying gas from Russia and paying in euros rather than the roubles required when trading with Gazprom.
A spokesperson for Latvijas Gaze, however, said on Friday the gas the company was buying was not from Gazprom. Latvijas Gaze would not name its provider, citing business confidentiality.
Latvijas Gaze did not immediately respond to a request for comment on Saturday following Gazprom's announcement.
In March, Putin said the world's largest natural gas producer would require countries designated as "unfriendly" in their stance on the conflict in Ukraine to pay for piped gas in roubles.
The European Commission -- which has warned that complying with Putin's order could breach European Union sanctions against Moscow -- has urged EU companies to continue paying in the currency agreed in their contracts with Gazprom, the vast majority of which are in euros or dollars.
(Additional reporting by Augustas Stankevicius in Vilnius; Editing by William Maclean)