Two underwater explosions, or shakings, were recorded in the Baltic Sea shortly before leaks were found in the Nord Stream 1 and 2 pipelines, which were pressurized with natural gas. Both pipelines were not operational.

The first shaking, measuring 2.3 on the Richter scale, was recorded southeast of Bornholm, a Danish island, the Guardian reported, citing Denmark's Geological Survey. The second, with a magnitude 2.1 earthquake, was reported northeast of the island.

Multiple Russian military vessels including two submarines were observed in the area near the time of the explosions.

The pipelines, while not in use, were filled with natural gas, and this is expected to be the biggest methane release by the energy sector ever, equating to .1% of total global annual emissions.