Sweden and Denmark: Pipeline leaks caused by "several hundred kilos" of explosives

What they're saying: "The magnitude of the explosions was measured at 2.3 and 2.1 on the Richter Scale, respectively, probably corresponding to an explosive load of several hundred kilos," the letter stated.

• "The possible impact on maritime life in the Baltic Sea is of concern, and the climate effect would likely be very substantial due to the significant volumes of greenhouse gas that are being released into the air."

State of play: The letter comes on the heels of NATO, the European Union and the North Atlantic Council labeling the leaks detected earlier this week a purposeful act of sabotage.

• The organizations have so far stopped short of naming a suspected culprit, but have vowed to investigate the cause.

• The pipelines are at the center of the energy crisis that has enveloped Europe since Russia's invasion of Ukraine. Nord Stream 1 is a crucial pathway for Russian gas to reach Europe, though Moscow stopped the flow earlier this month.

What we’re watching: The operator of the pipeline projected the leaks from Nord Stream 1 would continue until Oct. 2, according to the letter. An assessment of Nord Stream 2 is still pending.