Swedish and Danish authorities are investigating leaks from Russian gas pipelines at four locations discovered last week in the exclusive economic zones of Sweden and Denmark.

“There were detonations near Nord Stream 1 and 2, within the Swedish economic zone, resulting in extensive damage to gas pipelines,” the Swedish police said in a statement.

Some materials were seized at the scene and will now be analyzed, and the site is no longer cordoned off. The continuation of the investigation will show whether someone can be suspected and later prosecuted for this crime, added the police.

The Kremlin spokesman said today that he does not think the investigation can be objective without the participation of Russia, since Russia was not invited to participate. Danish police declined to comment on the investigation in Denmark’s exclusive economic zone.