The North Atlantic Treaty Organization (NATO) has formally labeled the damage to the Nord Stream 1 and 2 pipelines as "acts of sabotage."
Seismologists and other officials said that explosions were the likely cause of the damage to the pipelines, which carry Russian natural gas to Germany.
In its statement, the 27-nation bloc didn't say who might have been behind the leaks. The European Union also hasn't pointed to any nation.
Some Western government officials have suggested that Russia was behind the incident. However, Moscow has categorically denied those allegations and said it makes little sense to damage its own infrastructure and lose vast quantities of natural gas.
'Terrorist Act'Leaks from the two underwater pipelines have caused the release of millions of cubic tons of methane since they were reported earlier in the week. The pipelines currently weren't being operated but still contained large amounts of methane.
“This looks like some kind of terrorist act, possibly at the state level,” Peskov told reporters, according to TASS news. “This is an extremely dangerous situation that requires urgent investigation."
When asked on Sept. 28 about whether Russia was behind the leaks, Peksov described such allegations as "predictably stupid."
The NATO warning came as the Swedish coast guard confirmed a fourth leak on the pipelines off southern Sweden, which is in the process of joining NATO. The first leaks in the pipelines that extend from Russia to Germany were reported on Sept. 27, prompting energy companies and European governments to increase security.
The fear of further damage to Europe’s energy infrastructure has added pressure on natural gas prices, which had already been soaring. Russia, a major supplier to Europe, cut off deliveries earlier this year in retaliation for sanctions imposed after its invasion of Ukraine. That has caused widespread economic pain across the continent.