While the explosions took place in international waters, two of them were in the Danish exclusive economic zone and two in the Swedish zone.
Swedish and Danish officials have been conducting investigations since the explosions.
On Tuesday, Danish officials confirmed that there had been “extensive damage” to the Nord Stream 1 and 2 pipelines in the Baltic Sea off Denmark, and that the cause of the damage was “powerful explosions”.
Swedish authorities announced on October 6 that they had conducted an underwater inspection of the site and collected “pieces of evidence”, and that the inspection backed up suspicions of probable sabotage.
The pipelines, which connect Russia to Germany, have been at the centre of geopolitical tensions as Russia cuts gas supplies to Europe in suspected retaliation against Western sanctions over Moscow’s invasion of Ukraine.
World leaders have called the explosions an act of sabotage, while Moscow has sought to pin the blame on the West, suggesting the US stood to gain. Washington has denied any involvement.
The damaged Nord Stream pipelines discharged huge amounts of methane, a potent greenhouse gas, into the air for several days.
The Kremlin said on Tuesday that the international investigation into the explosions was set up with the intention of blaming Russia.
Dmitry Peskov, the Kremlin’s spokesman, said “elementary logic” showed that damage to the pipeline was a blow to Russia’s interests.
He said the investigation was being conducted “secretively” and without Moscow’s involvement.