European governments suspect Russian sabotage after three offshore lines of the Nord Stream pipeline system supplying Germany with Russian gas suffered “unprecedented” damage in a single day.
Poland's Prime Minister Mateusz Morawiecki blamed sabotage, while Danish Prime Minister Mette Frederiksen said she could not rule it out after three leaks were detected on the system designed to send gas to Europe.
"Today we faced an act of sabotage, we don't know all the details of what happened, but we see clearly that it's an act of sabotage, related to the next step of escalation of the situation in Ukraine," Mr Morawiecki said.
Swedish and Danish stations measured powerful underwater blasts in the area of the on Monday, Swedish broadcaster SVT reported as a German security official told Bloomberg the evidence suggested a violent act. German newspapers reported sources saying the leaks were as a result of a "targeted attack".
The damage caused gas leaks on the bed of the Baltic sea which pose a “danger to ships” and have forced shipping to be restricted. Investigations in Denmark, Sweden and Germany are underway.
Mykhailo Podolyak, one of Ukrainian president Volodymyr Zelensky's aides, blamed Russia for a "terrorist attack" against the EU.
"Russia wants to destabilise the economic situation in Europe and cause pre-winter panic," he said and added that the best response would be "tanks for Ukraine - especially German ones".
Asked if sabotage was the reason for the damage, Kremlin spokesman Dmitry Peskov told reporters: "No option can be ruled out right now."
"This is very concerning news," he added, "This is an issue related to the energy security of the entire continent."
Russia claimed last week it had foiled a planned terrorist attack by Ukraine on the TurkStream pipeline.
Both Nord Stream pipelines have been flashpoints in the dispute which has sent gas prices and the cost of living soaring, and led to accusations from European leaders that Vladimir Putin is weaponising energy supplies.
“The destruction that occurred on the same day simultaneously on three strings of the offshore gas pipelines of the Nord Stream system is unprecedented," Nord Stream AG, the operator of the network, said on Tuesday.
“It is not yet possible to estimate the timing of the restoration of the gas transport infrastructure,” the company added in a sign that Europe now faces a winter without Russian gas.
European gas prices rose by as much as 12 per cent on Tuesday after dropping for the last four days amid an escalating energy war with Moscow since the illegal invasion of Ukraine.
"There are some indications that it is deliberate damage," said a European security source, while adding it was still too early to draw conclusions. "You have to ask: Who would profit?"
Ms Frederiksen joined Poland's President Andrzej Duda and Prime Minister Mateusz Morawiecki in opening a valve of a yellow pipe belonging to the Baltic Pipe, a new system that will bring Norway's gas across Denmark and the Baltic Sea to Poland.
The new system is part of an effort to lessen EU dependence on Russian gas, which was brutally exposed by Vladimir Putin’s war in Ukraine.
Germany’s respected Die Welt newspaper said the timing of the leaks suggested sabotage. Die Welt said the Nord Stream 2 pipeline, which was meant to double Russian gas supplies to Germany, had been “partially destroyed”.
The Tagesspiegel newspaper quoted an insider involved in German federal investigations into the leak, who said such an act of sabotage could only be carried out by special forces and with the help of a submarine.
"Everything speaks against a coincidence [...]our imagination no longer produces a scenario that is not a targeted attack," the source said.
Denmark restricted shipping in a five nautical mile radius to the Nord Stream 2 pipeline after Sweden’s Maritime Authority issued a warning about two leaks on the Nord Stream 1 pipeline and also banned boats near the leaks, citing the risk of explosive gas.
Air traffic below 1,000 metres has also been banned near the restricted zone, and methane bubbles have been detected in the sea near the Danish island of Bornholm.
In June, the Danish military warned a Russian warship twice violated its territorial waters north of Bornholm, which is near both pipelines.
The gas bubbles reaching the surface have measured more than 100 metres in diameter.
The “extremely rare” leaks from the Nord Stream 2 pipeline in the Baltic Sea will continue for several days and perhaps even a week, the head of the Danish Energy Authority said.
Russia has already withheld gas supplies to Europe as it seeks to hit back for Western sanctions imposed for the war in Ukraine.
Nord Stream 1, which consists of two parallel lines with nameplate capacity of 27.5 billion cubic metres per year each, started supplying gas directly from Russia to Germany in 2011.
Flows from the pipeline were halted in August for maintenance and have not restarted, which Moscow blames on faulty equipment and Western sanctions. The pipeline was only working at 20 per cent of its capacity from July as relations worsened with the West.
The highly controversial Nord Stream 2 pipeline to Germany was built in September 2021 but has never been operational so no current supplies to Europe are affected by the leaks.
Germany refused to approve the project, which was long criticised for worsening Berlin’s dependence on Russian gas, just before Putin ordered his troops into Ukraine.
Neither pipeline was pumping gas to Europe at the time leaks were found but both still contain gas under pressure. In Nord Stream 2’s case this was so it would be ready to begin supplying Europe before the refusal to certify the project.
EU countries including Germany have been scrambling to secure alternative gas supplies and have been building up reserves in anticipation of the winter.