The first information about the leaks from Nord Stream “indicates acts of sabotage”.

A seismometer reading on the Danish island of Bornholm shows two peaks, at 0003 and 1700 GMT, followed by a low-level “whistle” on the day the Nord Stream 1 and 2 Baltic pipelines leaked one by one. In this photo posted on September 27. (Photo: German Georesearch Center / Reuters)

The Swedish National Seismological Network (SNSN) said Tuesday that it detected two explosions on Monday near the Nord Stream pipeline area.

The first explosion was recorded at 2:03 a.m. local time, and the second 17 hours later, at 7:04 p.m. on the same Monday, according to SNSN.

The network said that one of the underwater explosions caused a 2.3-magnitude earthquake.

According to SNSN, a similar seismic event was last recorded in the area in 2016. It added that this area is not usually used for defensive drills.

German geological research center GFZ told CNN that two earthquakes were recorded at similar times at a seismic station on the Danish island of Bornholm, again near reported leaks in oil pipelines.

Joseph Zenz, a spokesman for the Gulf Free Zone, told CNN that the first tremor occurred at 2:03 a.m. local time, and the second struck 17 hours later.

“It cannot be said whether there is any connection between the tremors and the leaks recorded in Nord Stream pipelines on Tuesday,” Zenz said.

The Swedish National Seismological Network said warnings about the gas leak came from the Maritime Administration at 1:52 pm and 8:41 pm on Monday, respectively, after ships detected bubbles on the surface.

Earlier on Tuesday, the Swedish Maritime Authority told CNN that three leaks had been identified in the Nord Stream 1 and Nord Stream 2 pipelines near Bornholm, warning ships to maintain a distance of 5 miles (8 kilometers) from the leaks. For aircraft with a safety altitude of 1000 metres.

The Danish Defense Command said in a statement, Tuesday, that “following the three gas leaks in Nord Stream gas pipelines in the Baltic Sea, exclusion zones were established around the leaks in the interest of maritime and air safety.”

Nord Stream AG, the pipeline operator, said in security documents released before the three gas leaks appeared in a day that the probability of a pipeline failure or leakage is “very low as one damage every 100,000 years.

The operator also said that “it is not expected that pipeline repairs will be necessary during Nord Stream’s minimum operating life of 50 years.”

Nord Stream 1 went into operation in 2012, and Nord Stream 2 was completed in 2021, but was never commissioned.