WARSAW, Poland (AP) Explosions rattled the Baltic Sea before unusual leaks were discovered on two natural gas pipelines running underwater from Russia to Germany, seismologists said Tuesday.

Danish Prime Minister Mette Frederiksen said her government regarded the leaks as the results of deliberate actions by unknown perpetrators. And other European leaders and experts pointed to possible sabotage amid an energy standoff with Russia provoked by the war in Ukraine.

The first explosion was recorded early Monday southeast of the Danish island of Bornholm, said Bjorn Lund, director of the Swedish National Seismic Network. A second, stronger blast northeast of the island that night was equivalent to a magnitude-2.3 earthquake. Seismic stations in Denmark, Norway and Finland also registered the explosions.

Theres no doubt, this is not an earthquake, Lund said.

Asked whether the incident constituted an attack on Denmark, Frederiksen replied that the leaks happened in international waters and the answer is thus no.

Asked who could be responsible for the leaks, Frederiksen said there is no information indicating who could be behind it.