Nord Stream pipeline leaks: Who or what is behind them?

The Danish Energy Agency has said it found two leaks this week in the Nord Stream 1 pipeline northeast of the island of Bornholm and a third and fourth in the Nord Stream 2 pipeline in Swedish waters southeast of the island.

"These are not small cracks, but really big holes," the agency said.

Meanwhile, Sweden's National Seismological Center detected two explosions in the Baltic Sea, with explosions also registered as far away as Finland. The leaks are pumping natural gas to the sea surface and an 8-kilometer (5-mile) exclusion zone for shipping has been set up around the island of Bornholm and flights below 1,000 metres banned in the area.

Quick to blame Russia

Sabotage appears to be the most likely cause of the leaks. European Commission President Ursula Von der Leyen called the leaks "sabotage," while Danish Prime Minister Mette Frederiksen said they were "deliberate acts."

Polish Prime Minister Mateusz Morawiecki said the leaks "probably mark the next step of escalation of the situation in Ukraine." US Secretary of State Antony Blinken has spoken to Danish Foreign Minister Jeppe Kofod about the "apparent sabotage."

Finland, meanwhile, is in urgent talks with four of the eight Baltic Sea region countries about the leak, Finland's minister for foreign affairs, Pekka Haavisto, told DW that "Sabotage cannot be ruled out, but this needs to be investigated as a criminal matter."

"The timing as Poland unveiled its Baltic Pipe pipeline [pumping Norwegian gas via Denmark to Poland] of the leaks is a reminder — if it was done on purpose — of how careful we need to be and how vulnerable we are," he added, speaking on the sidelines of a European Commission conference in the eastern Finnish town of Lappeenranta, 30 kilometers (18 miles) from the Russian border and 60 kilometers from the source of the Russian end of the Nord Stream pipeline in Vyborg.

Konrad Helmut Arz von Straussenburg, Germany's ambassador to Finland, told DW it was not right to jump to immediate conclusions. "This could mean a complete breakdown of the pipeline, or a partial suspension. We don't know yet. Rational calculations and cool heads are needed," he said.

That is a commodity in short supply in some parts.

"Sadly our eastern partner is constantly pursuing an aggressive political course," Poland's deputy foreign minister, Marcin Przydacz, said. "If it is capable of an aggressive military course in Ukraine, then it's apparent that acts of provocations in western Europe also cannot be ruled out."

Any evidence?

Several experts also blame Russia for the leaks, but no one has any proof so far. And there may never be any.

"Sabotage is of course suspected as all the evidence points to it," Anna Mikulska, an energy expert at Rice University in the United States, told DW. "And most analyses point to Russian sabotage."

If so, what would be the benefit for Russia?

"An inability to activate the pipelines undercuts any Russian leverage against Europe if the latter at any given point in time is in a critical situation with regard to gas supply, especially this winter and especially if the winter is harsh," Mikulska reasoned.

Chaos could be a motivating factor, according to Grzegorz Poznanski, director general of the Permanent Secretariat of the Council of the Baltic Sea States (CBSS). "This could of course be another way for Russia to execute a hybrid war," he said.

Mikulska agrees. "This could be a move to introduce chaos and uncertainty at the time when European gas markets have quieted just a bit after storage filled to higher-than-expected levels ahead of winter," she said.

The gas pipelines are owned by a company called Nord Stream AG, the majority of which is in the hands of the Russian state-owned company Gazprom. Russia has claimed it is unable to repair the pipelines due to anti-war sanctions, although Germany has said existing sanctions do not affect whether the pipeline repair operations.

The Nord Stream 1 and 2 gas pipelines also underwent dramatic falls in pressure coinciding with the leaks, the German geological research center GFZ said, perhaps indicating malfeasance at the Russian end. This also coincided with Poland rolling out its Baltic Pipe gas pipeline this week that reduces Poland's dependence on Russian gas.

"Breakage of gas pipelines is extremely rare," Danish authorities said in a statement.

Nord Stream 1 and 2 run from Russia to Germany at a depth of 70-90 meters (229-295 feet). The steel pipe has a wall of 4.1 cm (1.6 inches) and is coated with steel-reinforced concrete up to 11 centimeters thick.

"It certainly looks very suspicious and nothing Russia does would surprise me," Joanna Przedrzymirska, deputy director for the Polish Academy of Sciences' Institute of Oceanology, told DW.

Could the United States or Ukraine be behind it?

Arnold Dupuy, director of NATO's science and technology organization STO, said the damage may have been executed by an anti-Kremlin group from Ukraine.

Radoslaw Sikorski, a Polish MEP, suggested, meanwhile, that the US may have deliberately inflicted the damage, tweeting "Thank you, USA" next to an image of the Baltic Sea surface.

"The cases are truly mind-boggling," energy expert Mikulska added. "It seems that nobody would really benefit from them, as neither pipeline supplies gas to Europe after all, while the environmental cost of the event is truly horrible."

"However, the inability to use Nord Stream almost 'stabilizes' Germany's situation, in fact, not on a preferred level, but at least Germany now knows where it really stands," Rice argued.

Kremlin spokesperson Dmitry Peskov, meanwhile, has called for a prompt investigation, describing the leaks as "very concerning" and saying that "no option can be ruled out right now," including sabotage.