Nord Stream 1, which was inaugurated in 2011, stretches 1,200 kilometres under the Baltic Sea from the Russian coast near Saint Petersburg to north-eastern Germany. Until recently, it was by far the biggest Russian gas pipeline to Europe. However, it hasn't transported any gas since August, when Russia closed it down, officially due to "maintenance" reasons (Moscow says the sanctions have made it impossible to maintain the gas infrastructure properly, while Western governments have accused Russia of deliberately closing it down in retaliation for the West's sanctions and support for Ukraine).

Nord Stream 2 is a parallel pipeline that was completed in 2021 and was expected to enter into service in 2022 -- though Germany halted the project after the Russian invasion of Ukraine began. Neither pipeline was therefore operational at the time of the leaks, so the latter won't have any immediate impact on supplies, even though they're expected to further drive up gas prices.