Two "North Stream" pipelines that transport Russian natural gas to Europe leaked on September 26.
According to official Swedish news released on October 6, preliminary investigations show that the leak was caused by an explosion.
Where the explosion was caused is still unknown.
According to an exclusive report by Reuters on October 7, a U.S. Navy reconnaissance plane flew over the nearby waters hours after the first leak of the Nord Stream-2 natural gas pipeline.
According to previous reports by Russian media, U.S. military aircraft also flew over the pipeline several times in the period before the leak.