four undersea lines permanently out of use.
Moscow had asked Stockholm to be allowed to join the investigation, but both Sweden and Denmark rejected the idea of Russian participation. Construction of Nord Stream 2, designed to carry Russian gas to Germany, was completed in September 2021. Berlin shelved its certification just days before Moscow invaded Ukraine in February. Swedish and other European investigators say the attacks were carried out on purpose, but they have not said who they think was responsible. Moscow, without providing evidence, has blamed the explosions on Western sabotage. (Reporting by Reuters Editing by Gareth Jones)