Volkswacht Bodensee - Finland gas pipe likely damaged by 'mechanical force': police

The authorities declined to speculate on the specific nature of the force but said previously that "external" action had caused the Balticconnector pipeline rupture.

News of the line's breach prompted theories and questions after the blasts that last year breached three pipelines carrying natural gas from Russia to Western Europe.

"The damage appears to have been caused by a mechanical force, not an explosion," Detective Superintendent Risto Lohi from the National Bureau of Investigation told reporters.

"Nothing has been ruled out," Lohi added, referring to the precise cause of the rupture.

Finnish President Sauli Niinisto on Tuesday said the leak that caused the weekend shutdown of the undersea line had probably been caused by "external" activity.

An investigation into the cause of the leak, as well as the rupture of a telecommunications line that ran alongside it, is ongoing. It happened at a depth of tens of metres down.

The authorities said they have called on organisations and companies responsible for critical infrastructure to raise their level of preparedness.

"Damage to critical infrastructure, most likely deliberately caused, is a very serious matter," Janne Kankanen, CEO of National Emergency Supply Agency, said.

It will take at least five months to repair the pipeline, its operator said Wednesday, which will leave Finland totally dependent upon liquefied natural gas imports for the winter.

The Norwegian seismological institute NORSAR said Monday it had detected a "probable explosion" in the area of the leak. Finland's government cautioned against leaping to conclusions.

Last year, a sequence of underwater explosions resulted in the rupture of three pipelines in the Baltic Sea responsible for the transportation of natural gas from Russia to Western Europe.

Natural gas accounts for around five percent of Finland's energy consumption, mainly used in industry and combined heat and power production.

S.Spengler--VB