Nord Stream 1 pipeline gas flows into Europe dropped to zero on Wednesday morning, according to operator data, as part of a scheduled halt announced last week.

The halt will last through September 2, Russian state energy giant Gazprom confirmed Friday.

Nord Stream 1 is the largest pipeline bringing Russian natural gas supplies to Europe via Germany and was previously shut down for 10 days in late July for what Gazprom described as “annual maintenance.”

Wednesday’s outage has fueled concerns that Russia is deliberately cutting off supplies of its gas to Europe, in retaliation for Western sanctions over its war in Ukraine — an allegation Moscow denies.