The operators of Nord Stream 2 warned of a loss of pressure in the pipeline on Monday afternoon. That led to Danish authorities saying ships should avoid the area near the island of Bornholm.

Then on Tuesday, the operator of Nord Stream 1 said the undersea lines had simultaneously sustained “unprecedented” damage in one day.

The EU has said leaks in two major gas pipelines from Russia to Europe were caused by sabotage – but stopped short of directly accusing Russia.

Deliberate disruption would result in the “strongest possible response”, said the head of the European Commission, Ursula von der Leyen.

The EU has previously accused Russia of using gas supplies, and the Nord Stream line, as a weapon against the West.

The US Secretary of State Antony Blinken said he thought the leaks would “not have a significant impact on Europe’s energy resilience”.

Neither pipeline is transporting gas at the moment, although they both contain gas.

Mr Blinken did not directly accuse Russia – but said it would be in “no-one’s interest” if they were caused deliberately.

The president of the European Council, Charles Michel, echoed Ms von der Leyen’s message.

“Nord Stream sabotage acts appear to be an attempt to further destabilize energy supply to [the] EU,” he said on Twitter.

The Danish energy minister, Dan Jorgensen, said the leaks were likely to last for at least a week until the gas escaping from the pipes runs out. The investigation would begin after that.

Photo / AFP