The United States is "ready" to help European allies after leaks erupted from the Nord Stream 1 and 2 pipelines carrying Russian gas to western Europe, a senior White House official said Tuesday.

"I'm not going to speculate on the cause, and I know our European partners are investigating. We stand ready to provide support to their efforts," the official said, speaking on condition of anonymity. 

"This just drives home the importance of our efforts to work together to get alternative gas supplies to Europe and to support efforts to reduce gas consumption and accelerate true energy independence by moving to a clean energy economy."

Earlier today, Denmark's maritime traffic agency and Sweden's Maritime Authority reported a "dangerous" gas leak in the Baltic Sea close to the route of the inactive Nord Stream 2 pipeline, which experienced an unexplained drop in pressure.

The leak, southeast of the Danish island of Bornholm, "is dangerous for maritime traffic" and "navigation is prohibited within a five nautical mile radius of the reported position," the agency warned in a notice to ships.

Authorities in Germany, where the undersea pipeline from Russia makes land, said the energy link had experienced a drop in pressure, while its operator suggested that a leak may be the reason.

Nord Stream 2's operator mentioned pressure in the pipeline dropped from 105 to seven bars overnight.

Later, reports revealed that the Swedish National Seismic Network (SNSN) reported powerful underwater explosions in the area of gas leaks from the Nord Stream pipeline.

SNSN Director Bjorn Lund said as quoted by SVT that "there are no doubts that these were explosions."

“One explosion had a magnitude of 2.3 and was registered by dozens of monitoring stations in southern Sweden,” he stated. “You can clearly see the waves bounce from the bottom to the surface," Lund added.