Following the discovery of leaks from two Russian gas pipelines in the Baltic Sea, the Swedish Security Service said Thursday that the results of a preliminary probe have "strengthened the suspicions of serious sabotage."

A prosecutor said the suspicion of foul play was heightened after evidence from the site had been gathered.

Sweden's domestic security agency said the ongoing investigation confirmed that "detonations" caused extensive damage last week to the Nord Stream 1 and Nord Stream 2 pipelines, off the coasts of Sweden and Denmark.

The agency, which called what happened in the Baltic Sea "very serious," did not give details about its analysis.

Russian President Vladimir Putin accused the West of attacking the pipelines, which the United States and its allies have vehemently denied, noting that Moscow has the most to gain from wreaking havoc on Europe's energy markets.

A Kremlin spokesperson on Thursday said he did not think the investigation could be objective without Russia's participation as Moscow had not been invited to take part.

Finnish Foreign Ministry warns of further 'attacks'

Finnish Foreign Minister Pekka Haavisto said the world needs to be prepared for attacks on critical infrastructure after the apparent sabotage of the Nord Stream pipelines.

"This was clearly done by an entity with a state-like capacity," Pekka Haavisto told DW. "We need to be wary of similar attacks on other undersea cables, not only in the Baltic Sea, but trans-Atlantic ones."

Gas from the Nord Stream 2 pipeline southeast of Bornholm has stopped leaking, the Danish Energy Agency (DAE) said over the weekend.

Three other damaged parts of Nord Stream 2 and Nord Stream 1 pipelines are still pumping out gas into the sea. The pipelines are intended to supply Russian gas to Germany but have been suspended due to Russia’s invasion of Ukraine.

The Finnish minister said the Swedish and Danish assessments were that this was not a direct attack against them but an international challenge.

jsi/sms (AP, Reuters)