A preliminary investigation of damages on the two Nord Stream gas pipelines in the Danish part of the Baltic Sea shows that the leaks were caused by "powerful explosions", Copenhagen Police said in a statement on Tuesday.

The further investigation of the Sept. 26 ruptures of the Nord Stream 1 and 2 pipelines in Denmark's exclusive economic zone would be handled jointly by Copenhagen Police and Denmark's Security and Intelligence Service.

"It is still too early to say anything about the framework under which the international cooperation with e.g. Sweden and Germany will run, as it depends on several actors," Copenhagen Police said. (Reporting by Stine Jacobsen, editing by Terje Solsvik)