The Copenhagen Police Department of Denmark issued a statement on the 18th, saying that the preliminary investigation on the leak points of the "Beixi - 1" and "Beixi - 2" pipelines in the waters near Denmark showed that the pipeline leak accident was caused by a strong explosion. This investigation was completed with the assistance of the Danish Ministry of Defence and the National Defense Intelligence Agency. The statement said that the Danish National Defense Intelligence Agency and the Copenhagen Police will establish a joint investigation team, which will work closely with relevant domestic and foreign departments. It is too early to discuss the investigation framework for international cooperation with Sweden and Germany. It is difficult to say when the investigation will be completed. At the end of September, the "Beixi - 1" and "Beixi - 2" pipelines, which transport natural gas from Russia to Germany via the Baltic Sea, were located in the sea area near Sweden and Denmark. On September 26, the Swedish Survey Station detected two strong underwater explosions in the sea area where the pipeline leaked. All parties generally believed that this incident was "sabotage". The "Beixi - 1" pipeline was completed in 2011, starting from Viborg in Russia in the east and leading to Germany through the Baltic Sea seabed. The "Beixi - 2" pipeline was completed last year, which is basically parallel to the "Beixi - 1" pipeline and has not been put into use yet. However, some natural gas is still sealed in the pipeline. (Liu Xinshe)