The Danish and Swedish governments have said three gas leaks on the Nord Stream pipelines were “deliberate.”

Nord Stream refers to two double offshore natural gas pipelines in Europe running under the Baltic Sea from Russia to Germany. Officials said Tuesday that two leaks were identified on the Nord Stream 1, while one of the Nord Stream 2 pipelines showed a drop in pressure.

Gas leaks occurred near Bornholm, a Danish island to the east of the rest of Denmark.

Ukraine is blaming the leaks on Russia.

“The large-scale ‘gas leak’ from Nord Stream 1 is nothing more than a terrorist attack planned by Russia and an act of aggression towards the EU,” Kyiv’s presidential advisor Mikhaylo Podolyak wrote on Twitter.

Russia is seeking to “destabilize the economic situation in Europe and cause pre-winter panic,” he added.

Poland Prime Minister Mateusz Morawiecki said the events were “an act of sabotage.”

“The era of Russian domination in the gas sphere is coming to an end,” Morawiecki said. It was “an era that was marked by blackmail, threats and extortion.”

Germany also suspects the system was damaged by an act of sabotage amid the escalation between Russia and Europe in the former’s ongoing conflict with Ukraine.

Explosions preceded the gas leaks. The National Seismology Centre at the Uppsala University told Sweden’s public broadcaster SVT that it registered one blast early Monday southeast of the Danish island of Bornholm, and a slightly larger one later that night northeast of the island, CBC News reports.

The last explosion was equivalent to a magnitude-2.3 earthquake, it said.

The Danish Energy Agency expects the leaks from the pipelines to last “at least a week,” DW reports.

A video posted by American commentator Jack Posobiec on Twitter shows “a mysterious, frothing disturbance in the Baltic Sea in the vicinity of the Nordstream pipelines.”