Three leaks in the Nord Stream pipelines have sent gas to the Baltic Sea, with safety concerns leading to a five-mile exclusion zone around the affected area.
The EU said yesterday that the leaks were caused by sabotage, but stopped blaming Russia directly.
US intelligence agents this summer sent a “strategic warning” to countries, including Germany, about a possible attack.
The alert was not specific and did not specify a time or location for an attack, reports suggested.
European Commission President Ursula von der Leyen called the leaks an “act of sabotage.”
She said: “Any deliberate disruption to Europe’s active energy infrastructure is unacceptable and will trigger the strongest possible response.”
Josep Borrell, head of the European Union’s foreign policy, added: “All available information indicates that these leaks are the result of an intentional act.”
“Any intentional disruption to Europe’s energy infrastructure is completely unacceptable and will be met with a strong and united response.”
Nord Stream 2 operators warned of a pressure loss in the pipeline on Monday afternoon.
On Tuesday, the Nord Stream 1 operator said the submarine lines had sustained “unprecedented” damage in one day at the same time.
Kremlin spokesman Dmitry Peskov yesterday rejected suggestions that it was due to be “predictably and also predictably stupid”.
He said: “This is a big problem for us because, firstly, both lines of Nord Stream 2 are filled with gas – the whole system is ready to pump gas and the gas is very expensive. Now the gas is flying into the air.”
Russian state energy giant Gazprom warned it could cut natural gas flow to Europe via Ukraine, the last link still supplying buyers in Western Europe.
European Union countries were at odds yesterday (Wednesday) over whether or not to restrict gas prices in the bloc.
A group of 15 countries, including France, Italy, Spain and Poland, urged the Commission to propose a price cap for all wholesale gas transactions to help curb rising prices.
As a result of the attack on the gas pipelines, natural gas prices in Europe shot up again.
Neither pipeline currently carries gas to Europe, but some level of supply remains within the infrastructure.
Prof Piers Forster, director of the Priestley International Center for Climate at the University of Leeds, said: “Methane that leaks rather than burns is about 30 times worse for the climate.”
“The leak will have a strong immediate warming effect and also cause poor air quality. Compared to the daily leaks in the poorly maintained gas network around the world, it must be small.”
A video released by the Danish Armed Forces showed gas bubbles flowing to the surface of the Baltic Sea above Nord Stream 1 and 2.
Professor Joan Cordiner, a professor of process engineering at the University of Sheffield, said such a sudden large leak could only have come from a “sudden blow that cuts the pipe”.
In 2021, imports from Russia accounted for 4% of gas used in the UK, 9% of oil and 27% of coal.
But the European Union imported 155 billion cubic meters of natural gas from Russia in 2021, accounting for about 45 percent of EU gas imports and nearly 40 percent of total gas consumption.